handbook of crystal growth || selective area masked growth (nano to micro)

10

Selective Area Masked Growth

(Nano to Micro)

Handbook

Copyright

Jeong Dong Kim Xiaogang Chen James J Coleman

DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING UNIVERSITY OF ILLINOIS

URBANA IL USA

CHAPTER OUTLINE

101 Introduction 441

102 Methodology of SAG 444

1021 Growth Dynamics 444

of Crys

copy 2015

10211 Growth Modes 445

10212 MetalndashOrganic Chemical Vapor Deposition 447

10213 Vapor-Phase Diffusion and Surface Diffusion in SAG449

1022 Theoretical Methods to Model SAG 450

1023 SAG with MOCVD 456

1024 SAG in MBE 461

103 Applications of Selective Area Masked Growth 463

1031 Monolithically Integrated Dual-Wavelength Source ElectroabsorptionModulators and Y-Junction Coupler 463

1032 Inverse Quantum Dot Array 467

1033 IIIndashV NWs on a Silicon Substrate 470

104 Summary 472

Acknowledgments 474

References 474

101 IntroductionAdvanced epitaxial techniques such as metalndashorganic chemical vapor deposition

(MOCVD) and molecular beam epitaxy (MBE) enable control of the thickness of

semiconductor crystal growth uniformly to monolayer accuracy Many advanced

metamaterials such as multiple quantum wells (QWs) and superlattices are fabricated

routinely using such epitaxial growth techniques in both research laboratories and

industrial manufacturing facilities around the world Although these one-dimensionally

tal Growth httpdxdoiorg101016B978-0-444-63304-000010-X 441Elsevier BV All rights reserved

442 HANDBOOK OF CRYSTAL GROWTH

confined structures and devices are of great importance by themselves a more exciting

future for optoelectronic devices and systems requires planar integration of individual

devices to achieve compactness lower loss higher robustness and more superior per-

formance Selective area growth (SAG) or alternatively selective area epitaxy (SAE)

combines the benefits of both epitaxial growth and lithography techniques to enable

three-dimensionally defined and controlled growth of semiconductor materials

Lithography can be used to define device features in the plane perpendicular to the

direction of selectively grown crystal in the nanometer regime which allows the inte-

gration of a large number of devices monolithically on a single substrate It provides a

promising solution to the challenge of creating sophisticated integrated optoelectronic

and photonic systems

There are two basic types of SAG [12] The first type of SAG uses a dielectric insu-

lating mask to inhibit the deposition of materials wherever the mask is present [3]

Ideally epitaxial single crystal will grow uniformly only in the windows opened in the

mask In practice polycrystalline deposition may occur on the insulating mask

Polycrystalline growth on the mask can be avoided by choosing a halogen-based pre-

cursor and suitable growth conditions [24ndash6] Because the epitaxial growth process is

mass conserved no deposition on the mask leads to enhanced growth rate on the

unmasked area especially close to the boundary of the mask As a result if the di-

mensions of the window are large compared with the effective diffusion length of the

constituents the crystal layer deposited in the window may exhibit substantial lateral

variation in thickness and composition To predict the growth enhancement effect and

to control the thickness and composition of the deposited layers much effort has been

devoted to develop models accurately that describe the growth kinetics [7ndash19] High

lateral uniformity can be achieved for certain carefully designed structures and devices

[320] The second type of SAG involves depositing materials on a patterned substrate

without a mask Etching and lithography are used to define patterns on the substrate

before the deposition Localized epitaxial growth takes place in the patterned features

This technique has attracted a lot of attention because it may take only a single growth

step to form the desired structure But it is rather more difficult to model the preferential

growth of different species on different crystallographic planes In this chapter we focus

on the first type of SAG We start by reviewing briefly the history of the development of

SAG and discuss the current frontiers of this technology In the next section we intro-

duce the theoretical model that describes the selective growth kinetics in MOCVD

accurately We chose MOCVD as the exemplary technique because of its versatility in

fabricating semiconductor compounds and alloys We cover briefly the selective growth

model in MBE in Section 102 Section 103 includes provides a few examples that

illustrate how to use SAG to achieve optoelectronic integration

The idea of using photolithographic techniques to assist with the fabrication and

packaging of semiconductor devices dates back to the late 1950s [2122] During the

1960s selective epitaxial deposition of silicon and gallium arsenide was achieved in

different industrial research laboratories [23ndash25] In those early reports the focus was on

Chapter 10 bull Selective Area Masked Growth (Nano to Micro) 443

finding the appropriate growth conditions and source materials to achieve selective

growth of a single crystal in a desired region while avoiding deposition on the rest of the

substrate During the late 1960s MOCVD emerged as a promising technique in the

production of a wide range of single crystal layers of compound semiconductor materials

[26ndash29] Soon after this invention a few research groups studied the SAG of GaAs and InP

using MOCVD [30ndash41] It was found experimentally that the selectivity is highly

depending on the substrate temperature the chamber pressure and the local geometry

of the mask windows The primary issues with SAG using MOCVD were the variations in

the thickness and the composition of the single crystal grown in the windows opened in

the mask because these variations affect the uniformity and the abruptness of the

desired band structure of the device adversely and in turn degrade its performance

Two growth mechanisms were proposed to explain the kinetics of the local growth

enhancement surface diffusion [42] and vapor-phase diffusion [71316] During the

early 1990s Kayser [43] and Colas et al [44] both provided convincing experimental

results showing that vapor-phase diffusion is the dominant effect in SAG using MOCVD

Theoretical models based on vapor-phase diffusion were developed and excellent

agreement was obtained with experimental results on growth rate enhancement (GRE)

surface curvature and the composition variation of the epitaxial layer [12131645]

More advanced and complex nonlinear models that took into account surface reaction

kinetics were proposed to achieve even better predictability on growth rate nonunifor-

mity during the 2000s [1945] These models provide guidance for researchers to develop

more sophisticated structures and advanced devices and systems using selective area

MOCVD (SA-MOCVD) On the other hand the list of materials systems that can be

grown using SA-MOCVD has been expanded from GaAs and InP to virtually all IIIV and

IIVI semiconductor compounds and alloys

The field of integrated optoelectronics gained great momentum during the past

30 years as a result of explosively increased demands for higher speed information

transmission faster information processing and retrieval and larger capacity in infor-

mation storage As the SA-MOCVD technique matured new device concepts and more

complex system designs have been demonstrated to meet these challenges Individual

electronic and optoelectronic components such as the heterostructure field effect tran-

sistor distributed feedback laser and electro-optical modulator detector and waveguide

were fabricated successfully using SA-MOCVD [46ndash56] The performance of these devices

has improved consistentlyMuch effort has been devoted to integrating these components

on a single substrate to build an on-chip optoelectronic system SA-MOCVD has been

used to integrate laser diodeswithwaveguidesmodulators and detectors [148ndash5057ndash62]

The ultimate goal of integrated optoelectronics is to build low-power consumption

high-data transmission rate on-chip interconnection networks that are compatible with

mature ComplementaryMetal Oxide Semiconductor (CMOS) electronic systems This is a

major force that keeps driving forward the research in SA-MOCVD techniques

One important extension of SA-MOCVD being studied heavily in recent years is the

fabrication of reduced-dimension materials such as nanowires (NWs) and quantum


dots (QDs) with enhanced performance compared with traditional bulk or QW-based

devices QD-based semiconductor lasers require a much lower current density to ach-

ieve population inversion and are much less sensitive to thermal effects The very small

lateral dimension of QDs allows them to be fabricated from more highly strained ma-

terials and in turn to achieve the longer wavelength emission necessary for fiber-optic

telecommunications applications Patterned QDs have been fabricated using

SA-MOCVD [6364] Room-temperature lasing operation has been observed using a

buried heterostructure (BH) with the patterned QDs as the active layer A novel structure

complementary to patterned QDsmdashnamely the inverse quantum dots array (IQDA) or

nanoporemdashhas also been fabricated successfully using SA-MOCVD [6566] The structure

is referred to as inverse QDs in the sense that the lower energy dot regions and the higher

energy barriers in the patterned QDs have been interchanged within the plane of the

active layer The unique properties of the IQDA include the delocalization of the carrier

wave function in the lower energy framework and the larger effective density of elec-

tronic states Forbidden subbands formed within conduction and valance bands of the

base QW have been demonstrated both theoretically and experimentally in IQDA It can

be thought of as an electronic analog to the photonic crystal Another recent advance-

ment in SA-MOCVD is the growth of IIIndashV NWs on silicon substrate which allows the

integration of direct band gap IIIndashV materials with mature silicon electronic and pho-

tonic devices In 2004 Martensson et al successfully demonstrated the heteroepitaxial

growth of GaP on Si (111) and Si (001) substrates After this pioneering work epitaxial

growth of NWs consisting of other IIIndashV binary and ternary compounds on silicon has

been reported by many groups worldwide Both the vaporndashliquidndashsolid method and

SA-MOCVD have been used for this heteroepitaxial growth An example is given later in

the chapter to illustrate the processes of SA-MOCVD growth of a corendashmultishellndash

NWs-based light emitting diode (LED) The integration of IIIndashV compounds on a silicon

substrate helps to overcome the material limitations of siliconmdashthe inefficient light

generation and the lack of suitable heterostructures to achieve high-speed operation in

electronic and photonic devices This integration technique when mastered will form

the building block of the next-generation electronic and photonic devices and systems

102 Methodology of SAG1021 Growth Dynamics

Conventional epitaxial growth techniques allow high-quality and uniform material

deposition parallel to the exposed substrate surface The dynamics involved in these

epitaxial processes can be well described under many conditions by the mass transport

limited model However the presence of a dielectric mask on the wafer surface modifies

growth mechanisms significantly The growth rate may vary considerably from the

center of the exposed substrate to the boundary region defined by the dielectric mask

This adds new difficulty in designing and fabricating spatially confined structures and


devices using SAG To understand more completely the growth dynamics in SAG several

growth models have been proposed by different groups [121467ndash71] In this section we

first examine the different growth modes and their corresponding suitability for growing

confined structures Then we review briefly the MOCVD chamber geometry and the

growth conditions important for our later discussion on SAG Last we introduce the

diffusion processes that define the growth dynamics and that must be considered to

understand the SAG technique

10211 Growth ModesUnderstanding growth modes is important for designing SAG structures because crystals

grown in different modes exhibit a distinctive interface structure and defect properties

For selectively grown homostructures and low-lattice mismatched materials uniform

growth is possible because the strain at the interface between the substrate and the

deposited layer is minimal Lower dimension structures such as QWs quantum wires

and QDs can be designed through dielectric mask patterning For heterostructures

consisting of a large-lattice mismatched layer strain at the interface has to be considered

during the crystal growth process Buffered strain release layers may be used to fabricate

the desired structure However the surface strain in the heterostructure can be bene-

ficial in creating selectively grown low-dimensional structures For example QDs instead

of a QW could be grown in the patterned dielectric mask if the lattice mismatch of two

different materials is large

The range of different growth modes was first introduced by Bauer in 1958 [72] It is

determined by the lattice mismatch between the substrate and the growth layer on top of

it There are three different growth modes in general Frankndashvan der Merwe (FM)

VolmerndashWeber (VW) and StranskindashKrastanov (SK) as illustrated in Figure 101

(a)

(b)

(c)FIGURE 101 Illustration of different growth modes Frankndashvan der Merwe in which a uniform film growth occursby having minimal lattice mismatch (a) VolmerndashWeber in which the deposited material forms islands (b) andStranskindashKrastanov in which a pseudomorphic film is grown on the substrate until the film thickness reaches thecritical thickness and transitions to island growth (c) [73]


The pseudomorphic layerrsquos misfit f first used by Frank and van der Merwe in 1949

[74] is defined as

f frac14 Da0

a0

(101)

where a0 is the lattice constant of the grown crystal which is normally called the strain

layer and Da0 is the lattice constant difference between the substrate and the strain

layer

When f is smaller than the critical misfit fc the strain at the interface is negligible and

the pseudomorphic film is stable As a result monolayer-by-monolayer growth occurs

This growth mode is the FM mode When f exceeds fc and the thickness of the film

reaches its critical thickness (hc) the pseudomorphic film becomes unstable and the

strain energy is relaxed by forming dislocations the growth mode transits from FM to SK

The critical thickness was proposed by Matthews and Blakeslee [75] and it is defined as

hc frac14 a0

2ffiffiffi2

ppf

eth1 025vTHORNeth1thorn vTHORN

ln

hc

ffiffiffi2

p

a0

thorn 1

(102)

where v is Poissonrsquos ratio defined as

v frac14 c12c11 thorn c12

(103)

where c11 and c12 are the elastic coefficients of the compounds

The VW growth mode occurs when the pseudomorphic film is initially unstable

forming the dislocations immediately without having any FM growth because of a large-

lattice mismatch between the substrate and the growth layer

A well-known example of the FM growth mode is AlAs on a GaAs substrate The lattice

constant of AlAs is 56608 A and the lattice constant of GaAs is 565325 A where f is

approximately 00013 Awell-knownexample of SK andVWmodes are InxGa1xAs onGaAs

and InAs onGaAs respectively The lattice constant of the InAs is 60583 A and the value of f

is 00668when it is grownonGaAs This value is approximately five times larger than the f of

AlAs-GaAs When InxGa1xAs has a composition of 20 the value of the lattice constant is

57343 A and the value of f is 001413 which is between the values of f for InAs-GaAs and

AlAs-GaAs heterostructures With either FM or subcritical SK growth modes QWs can be

grown selectively on a substrate and this is shown in 852-nm and 980-nm SAG laser ap-

plications that makes use of AlxGa1xAs-GaAs-AlxGa1xAs and GaAs-InxGa1xAs-GaAs

double heterostructures respectively [207677] Selectively grown InAs self-assembled

QDs on a GaAs substrate is an example of using SAG with VW growth mode [78]

Separately from maskless growth SAG gives another freedom in fabricating low-

dimensional structures Growth of low-dimensional structures with FM and SK modes

becomes possible by growing material on top of a nano-scale patterned mask and this is

demonstrated in selectively grown NW and QD arrays [7980] The density and unifor-

mity of the NW and QD can be controlled in this manner to achieve the required

consistency in device performance


10212 MetalndashOrganic Chemical Vapor DepositionSAG can be achieved using both MBE and MOCVD We chose MOCVD as the exemplary

system for SAG because the system is relatively simple and more cost-effective and

more important it is possible to achieve great selectivity compared with MBE In

addition MOCVD is very versatile in growing almost all IIIndashV and IIndashVI compound

materials with very high quality In this section we describe variables in MOCVD

systems that affect SAG growth We provide a comparison of SAG using MOCVD and

MBE in Section 1024

Figure 102 shows cross-sectional views of the vertical and horizontal MOCVD reactor

chambers The chemicals coming from the input port of the chamber undergo pyrolysis

reaction at and above the substrate which is placed on top of a heated susceptor The

elemental materials produced from the reaction are deposited epitaxially on the

substrate The by-products of the reaction exit through the exhaust line

(a)

(b)

Baffle

SusceptorRF coil

RF coil

Susceptor

FIGURE 102 (a b) Schematic of the cross-section view of a typical vertical reactor chamber (a) and a horizontalreactor chamber of the metalndashorganic chemical vapor deposition system (b) [81] RF radiofrequency


The pyrolysis reaction between the metalndashorganic compound and the hydride in SAG

is the same as that in maskless growth and it can be generalized by the following

equation

RnMthorn YHnMY thorn nRH (104)

where R is the organic radical typically a methyl (CH3) or an ethyl (C2H5) group M and Y

are the constituent species for the deposited solid and n is an integer For example the

binary compound GaAs formation from trimethylgallium ((CH3)3Ga) and arsine (AsH3)

reaction is shown in Eqn (105)

ethCH3THORN3Ga thorn AsH3GaAs thorn 3CH4 (105)

The ternary compounds are formed by introducing the additional component in the

proper stoichiometric ratio AlxGa1xAs formation from trimethylgallium ((CH3)3Ga)

trimethylaluminum ((CH3)3Al) and arsine (AsH3) is shown in Eqn (106)

xethCH3THORN3Althorn eth1 xTHORNethCH3THORN3Gathorn AsH3AlxGa1xAsthorn 3CH4 (106)

SAG strongly depends on the system pressure the partial pressure of precursors and the

growth temperature These parameters affect the diffusion length of the precursors

which in turn determines the thickness and the composition of the grown film A method

for calculating the diffusion length is given in Section 1022

The growth temperature and system pressure are controlled in a variety of ways

[81ndash83] The partial pressure of the precursors defines the delivery rate of the

metalndashorganic sources which normally go through a bubbler system before they are

mixed in the chamber The partial pressure can be controlled by adjusting the bubbler

temperature The partial pressure can obtained using

Ppartial frac14 10ethab=T THORN 101325

760mbar (107)

where T is the bubbler temperature and a and b are the metalndashorganic precursor

parameters Common metalndashorganic precursor parameters are provided in Table 101

Table 101 Partial Pressure Parameter Values forCommon Metal Organic Precursors [8485]

Precursor a b (K)

TMGa 807 1703TEGa 8080 2162TMAl 822 2134TMIn 1052 3014DMZn 780 1560DEZn 8280 2109TMP 77627 1518TMSb 773 1709TESb 790 2183

d

FIGURE 103 Cross-section view of a susceptor in the vertical reaction chamber and the boundary layer ofthickness d formed above the susceptor Arrows indicate the flow of the gas inside the growth chamber


Growth pressure temperature and flow rate act together to determine the thickness

and the shape of the boundary layer formed above the substrate Figure 103 illustrates a

schematic boundary layer formed above the susceptor with an average thickness of d

The details of how to calculate growth thickness and composition in SAG are described

in Section 1023

10213 Vapor-Phase Diffusion and Surface Diffusion in SAGIn SAG the growth regime is perturbed by the presence of the mask Vapor-phase

diffusion and surface diffusion are the two primary transport mechanisms that influ-

ence material deposition in the window area Figure 104 illustrates the three processes

taking place in the boundary layer that contribute to the transport of precursors in the

proximity of the mask window

(a)(b) (c)

Oxide mask Oxide maskWindow

Substrate

X

z

FIGURE 104 Growth mechanisms of SAG at the cross-section of a substrate with an oxide mask and window Thediffusion mechanisms are illustrated as follows (a) The precursor reaches the window area (b) The precursor isdesorbed from the mask and returns to the boundary layer in the vapor phase and then migrates to the windowthrough vapor-phase diffusion (c) The precursor is adsorbed on the mask and surface diffuses toward thewindow


The growth species migrate by vapor-phase diffusion within the boundary layer The

diffused species can reach either the mask or the window area The material that reaches

the window area directly undergoes the normal pyrolysis reaction and deposits with a

crystalline structure (Figure 104(a)) The material that reaches the mask can be either

adsorbed and migrate toward the window area via surface diffusion (Figure 104(c)) or be

desorbed quickly The desorbed material returns to the gas phase and will in the

aggregate diffuse toward the mask window by vapor-phase diffusion (Figure 104(b))

The rate of adsorption is the product of the precursor partial pressure the number of

vacant atomic sites and an adsorption constant whereas the rate of desorption equals

the product of the number of occupied sites and a desorption constant [86]

The growth process is governed by the net effect of these diffusion processes The

diffusion length determines the average distance that a source molecule can travel freely

either in the vapor phase on top of the substrate or along the substrate surface which is

defined as Dk where D is the diffusion coefficient specific to different processes and

different growth species and k is the reaction rate constant that determines the precursorrsquos

sticking probability when the precursor is diffusing on the substrate Typical diffusion

lengths of vapor-phase and surface diffusion are on the order of 100 and 1 mm respectively

[87] The theoretical estimation of diffusion length is described in Section 1022 and some

measured diffusion lengths for various types of precursors are given in Section 1023

The dimensions of the SAG mask and window must be designed carefully depending

on the diffusion lengths If the width of the mask is longer than the vapor-phase or

surface diffusion length some material may be deposited on the mask often with a

polycrystalline structure [10] It has been proposed and demonstrated experimentally

that halogen-based precursors can be used to avoid such polycrystalline deposition

because of the high volatility of the precursor and the near-equilibrium growth condition

used [24588]

1022 Theoretical Methods to Model SAG

The concepts of vapor-phase diffusion and surface diffusion in SAG were introduced by

Oldham and Holmstrom in 1967 [69] and by Silvestri et al in 1972 [68] Early SAG models

assume that the nonuniform film thickness and the GRE in SAG is a result of changes in

either the vapor-phase diffusion or the surface diffusion However simulating SAG using

only one diffusion process does not match experimental results accurately An SAG

model that accounts for both vapor-phase diffusion and surface diffusion along the mask

was developed using advanced numerical techniques by Coronell and Jensen in 1991

[67] Their work showed how reactor conditions and mask material affect SAG by

considering metalndashorganic reactant parameters such as sticking probabilities residence

times and surface diffusion lengths However this model is impractical because most of

the required parameters to construct the simulation cannot be measured directly or

precisely A practical SAG model was introduced by Gibbon et al in 1993 [12] The

primary assumption in Gibbonrsquos model is that there is no reactant sticking to the mask


In addition an adjustable kinetic constant is incorporated to allow for better fitting of the

experimental results A precise SAG model using conformal mapping was introduced by

Korgel and Hicks in 1995 [14] Their model considers the adsorption of group III re-

actants on the masks [89ndash91] and the capture probability that describes the likelihood of

a metalndashorganic molecule adsorbed on the mask diffusing into the boundary region The

nonlinear surface kinetics in both two and three dimensions was proposed by Song et al

in 2007 [70] and was demonstrated in InAs and InP by Wang et al in 2008 [19] In the

linear kinetic model only the growth temperature is considered as the factor that de-

termines the value of the surface reaction rate constant k whereas in the nonlinear

model both growth temperature and partial pressure of the precursors are used to

determine the value of k and the values of D and k The growth profiles are

then simulated using the Langmuir-Hinshelwood model to analyze the surface kinetics

of SAG

In this section we chose to introduce the vapor-phase diffusion model developed by

Gibbon et al [12] because the simulation results from this model have shown very good

agreement with experiments In addition this model is widely used in reported IIIndashV

binary ternary and quaternary compound characterizations to compare simulation

with experimental data and to develop advanced SAG models [10131517189293] An

MOCVD system with a vertical reaction chamber is assumed in the following discussion

Readers interested in exploring the full details of all these models are encouraged to

study the original publications listed in the references

In Figure 105 n is the precursor concentration c and d are the width and thickness of

the boundary layer respectively w is the width of the window D is the mass diffusivity

in the vapor phase and k is the rate of adsorption of precursors per unit precursor

concentration above the wafer surface This vapor-phase diffusion model is suitable for

describing both two-dimensional (2D) and three-dimensional (3D) systems The 2D

model can be used when the oxide stripe length is very large with respect to the stripe

width In this case diffusion in the direction parallel to the oxide stripes can be ignored

A 3D model must be used if such an approximation is not valid A 2D model was

introduced by Gibbon et al [12] A 3D model was introduced by Alam et al [94] on a

wafer patterned with masks of nonuniform width

The equation to model the steady-state diffusion of the precursor concentration in

3D is

v2n

vx2thorn v2n

vy2thorn v2n

vz2frac14 0 (108)

To simplify the calculation the gas concentration is assumed to be uniform far above the

mask At the top of the boundary layer the precursor concentration is set to be constant

at n0 This implies that the distance from the window to the upper border of the

boundary layer has to be sufficiently large to avoid any perturbation from the mask

Mathematically it is shown as

njzfrac14d frac14 n0 (109)

n0 = Constant outside boundary layer

n = n0

n = f(xy) inside boundary layer

dndx = 0

dndx = 0

dndz = 0 dn

dz = 0

dn kndz D=

W

Oxide mask Oxide mask

Substrate

c

x0

z

Bou

ndar

y la

yer

d

FIGURE 105 Cross-section of the vapor-phase diffusion model on a substrate with an oxide mask and windowwhere n is the concentration of precursor c is the width of the boundary layer d is the thickness of the boundary


The precursor concentration does not change at the borders of the boundary layer in

the lateral direction and can be described in Eqn (1010)

vn

vx

xfrac140C

frac14 0 (1010)

Two mechanisms take place on the substrate inside the boundary layer during growth In

the first case the precursor is not incorporated when it reaches the dielectric mask

surface The boundary equation is derived from Fickrsquos law and it is shown in Eqn (1011)

vn

vz

zfrac140

frac14 0 (1011)

In the second case the precursor is incorporated at the semiconductor surface The

boundary condition is derived from a combination of Fickrsquos law and the Langmuir

isotherm and it is shown in Eqn (1012)

Dvn

vz

zfrac140

frac14 kn (1012)

The profile of the precursor concentration is determined by the parameter Dk which

can be thought of as the effective diffusion length The value of Dk can be estimated

either by theoretical calculation or by fitting the experimental result

layer w is the width of the window D is the mass diffusivity constant and k is the surface reaction constant [16]


Theoretically the binary diffusion coefficient D at low pressure can be estimated by

solving the Boltzmann equation and this was introduced by Chapman and Enskog and

itrsquos described by Poling et al [95] It can be defined as

DAB frac14 3

16

4pkBTMAB

1=2

nps2ABUD

fD (1013)

where MA and MB are the molecular weights of gases A and B respectively n is the total

concentration of mixture molecules A and B kB is the Boltzmannrsquos constant T is the

absolute temperature UD is the diffusion collision integral sAB is the characteristic

length of the intermolecular force law and fD is the correction term The reduced

molecular weights of gases A and B MAB can be calculated using

MAB frac14 2MAMB

MA thornMB

(1014)

The value of UD is a function of temperature and it depends on the intermolecular force

law between the colliding molecules The value of fD is in the order of unity whenMA and

MB are of the same order (typically between 10 and 102) otherwise the value may vary

from 10 to 11

For the case when ideal gas law is applicable and MA and MB are of the same order

by assuming that fD is unity Eqn (1013) can be simplified to

DAB frac14 000266T 3=2

PM1=2AB s2

ABUD

(1015)

The values of sAB and UD can be found by using the Lennard-Jones potential theory

which describes the potential of the ideal gas viscosity and it is shown in Eqn (1016)

j frac14 4ε

sr

12sr

6(1016)

where ε is the energy and s is the length of the Lennard-Jones theorem The value of sABcan be calculated from the s value of each type of molecule using Eqn (1017)

sAB frac14 1

2ethsA thorn sBTHORN (1017)

Table 102 shows the calculated values of the Lennard-Jones parameters The approxi-

mation of the value of UD was reported by Neufield et al in 1972 and it is shown in

Eqn (1018) [96]

UD frac14 106036

ethT THORN01561 thorn0193

eeth047635T THORN thorn103587


eeth176474T THORN (1018)

where T is a function of the Lennard-Jones parameters as shown in Eqn (1019)

T frac14 kbT

εAB

(1019)

Table 102 Lennard-Jones Parameters forMetalndashOrganic Sources and Carrier Gases [97]

Compound M (gmol) εkb (K) s (Aring)

TMAl 7209 483 582TMGa 11483 398 568TMIn 15993 494 576TEAl 11417 555 651TEGa 15691 504 664TEIn 20201 553 669AsH3 7795 2598 4145PH3 3400 2515 3981SiH4 3212 2076 4084H2 2016 597 2827


The surface reaction rate constant k can be calculated using Eqn (1020) [98]

k frac14 1

4

h

1 h=2

ffiffiffiffiffiffiffiffiffiffiffi8kBT

pM

rfrac14 k0e

eth EakBT

THORN (1020)

where h is a sticking coefficient T is an absolute temperature Ea is a surface reaction

activation energy and M is the molecular weight

As seen in Eqn (1015) the value ofD is inversely proportional to the growth pressure P

and proportional to growth temperature to the power of 32 The value of k decreases

exponentially as the temperature increases and this can be seen in Eqn (1020) The values

of both D and k are specific to a particular material and depend on the values ofM and s

The Chapman-Enskog theory also indicates that D depends on the type of the metalndash-

organic source For example the difference in the diffusion coefficient between trime-

thylgallium and MMGa is around 10 according to the Chapman-Enskog theory [99]

The value of Dk can be obtained by fitting the experimental results with the

simulation model (Eqns (108)ndash(1012)) Alternatively the value of D and k can be

approximated by using Eqns (1013) and (1020)

It is important to collect values of Dk for different growth conditions for precursors

to obtain the simulated growth profile of SAG The collected values of Dk are presented

in Figure 107 and 108 The typical value of Dk is 85ndash190 mm for Ga and 10ndash70 mm for In

[129499ndash101] As can be seen from Figure 107 and 108 Dk is smaller at greater

pressures which yields large in-plane modulation of the precursor concentration at the

window edge Conversely it is relatively large at low pressures and hence results in a

smaller modulation of the precursor concentration

As a result of the conservation of mass GRE occurs at the edges of the window region

For nonselective growth the density of reactants varies only normal to the growth

surface and reactants arriving at the top of the boundary layer diffuse uniformly toward

the substrate However in SAG the distribution of reactants varies not only in the

transverse direction but also in the lateral direction as a result of the presence of the

1

2

3

1

3

2

4

1

2R

OIMcalculation

OIMcalculation

OIMcalculation

A1InAs

GaA1As

A1GaInAs(a)

(b)

ndash300 ndash200 ndash100 0x μm

100 200 300

(c)R

R

4

3

FIGURE 106 Simulated and measured growth rate enhancement profiles of ternary and quaternary compounds(AlGaAs InAlAs AlGaInAs) for a dual-stripe mask with a window width of 30 mm and mask stripe widths of 80and 120 mm The samples were grown at 650 C and a growth pressure of 150 mbar [100] Optical interferometermicroscopy (OIM)


dielectric mask This nonuniformity in reactant concentration exists in both the lateral

and transverse directions which increases the growth rate in the mask window

The diffusion length determines the GRE which is proportional to the precursor

concentration profile within the boundary layer

The value of the GRE can be obtained by normalizing the selectively grown layer

thickness at a given position to the thickness of the nonselectively grown layer as shown

in Eqn (1021)

GRE frac14 T ethx yTHORNTplanar

frac14 Rethx yTHORNRplanar

frac14 nethx yTHORNnsp

(1021)

300

250

200

150

100

50

500 600 700 1000 1100 1200 13000

Dk

(μm

)

T (ordmC)

GaAs (100 mbar)GaAs (200 mbar)

GaN (200 mbar)GaN (100 mbar)

FIGURE 107 Extracted diffusion lengthsof GaAs and GaN at 100 mbar and200 mbar respectively at differenttemperatures showing that Dk is lowerat greater pressures for both GaAs andGaN [99101]

600 650 700 750

T (ordmC)

800 850 900

InN (200 mbar)AIAs (200 mbar)

300

250

200

150

Dk

(μm

)

100

50

0

FIGURE 108 Extracted diffusion lengths ofInN and AlAs at 200 mbar versustemperature showing the nonlinearrelationship in various precursors [101102]


where T is thickness and R is growth rate

The GRE profile is typically derived using

GRE frac14 n

nsp

frac14 n

n0

1thorn d

D=k

(1022)

where nsp is the precursor concentration in the vicinity of the surface and it is derived

analytically as shown in Eqn (1023)

nsp frac14 n0

1thorn d

D=k

1

(1023)

The magnitude of the GRE is inversely proportional to the carrier concentration at the

top of the boundary region and the effective diffusion length whereas it is proportional

to the thickness of the boundary layer

A small Dk value yields a steep GRE profile and a large precursor concentration

adjacent to the mask If Dk is much larger than the thickness of the boundary layer

the quantity in the parentheses on the right-hand side of Eqn (1022) becomes

negligible As a result the GRE becomes constant and is independent of the mask

geometry

1023 SAG with MOCVD

The theoretical model introduced in the previous section shows that SAG is determined

by the effective diffusion length Dk which is dependent on the growth conditions of

pressure temperature and material parameters from the different precursors In this

section experimental data of binary ternary and quaternary compounds are presented

and compared with theoretical calculations


Figure 107 shows the effective diffusion length as a function of growth temperature at

different growth pressures The effective diffusion lengths are smaller at 200 mbar than

those at 100 mbar for both GaAs and GaN which indicates that Dk decreases as the

pressure increases This agrees with the theoretically calculated values of D and k using

Eqns (1013) and (1020) where D is inversely proportional to the growth pressure and k

is not related explicitly to the growth pressure

The dependence of Dk on the growth temperature is more complex Figure 108

shows the surface diffusion lengths of InN and AlAs at 200 mbar versus temperature

Both D and k have a nonlinear relationship with temperature So does the effective

diffusion length Dk This is seen clearly in both Figures 107 and 108 In Figure 107 the

Dk value of GaAs at 200 mbar decreases as the temperature increases from 560ndash590 Cand it increases from 600ndash640 C The Dk value of GaN at 200 mbar increases when the

temperature changes from 1000ndash1100 C and it increases when the temperature changes

from 1100 to 1150 C Similarly in Figure 108 the Dk value of InN at 200 mbar

decreases when temperature changes from 600 to 625 C and it increases when the

temperature changes from 625ndash700 C The Dk of AlAs increases as the temperature

increases from 600 to 900 CTable 103 shows the extracted surface diffusion length of In and Ga for InxGa1xAs at

40 mbar and 1013 mbar for various temperatures The Dk of Ga is greater than that of

In at given temperatures and pressures This can be confirmed by comparing the nu-

merical data in Table 102 The molecular mass of the trimethylindiummolecule is larger

than that of trimethylgallium and s is also longer in trimethylindium These parameters

have inverse proportionality for D and k as shown in Eqns (1015) and (1020) which

leads to the smaller diffusion length for In The results from Table 103 also indicate that

the precursors in both ternary and quaternary compounds do not have the same

diffusion length which contributes to the compositional variation along the window

regions when the distance from the edge of the mask to the center of the window exceeds

the surface diffusion length of the precursors

By knowing the specifics of the surface diffusion length it is possible to estimate how

the growth profile will look in SAG SAG of various types of precursors has been studied

by different groups [188792939899102104ndash116]

Table 103 Extracted Surface Diffusion Length of In and Ga from InxGa1xAs TernaryCompound at 40 mbar and 1013 mbar Both Showing the Ga Dk is larger than the InDk Indicating the Cause of the Composition Variation Along the Window Region[92103]

Temperature (C) In (40 mbar) Ga (40 mbar) In (1013 mbar) Ga (1013 mbar)

400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate

FIGURE 109 (a b) Cross-section image of a dualoxide stripe mask with a dielectric mask beforegrowth (a) and after growth (b) illustratinggrowth rate enhancement


To study systematically the effect of mask patterning on SAG some geometrically

simple patterns have been commonly used Among these patterns the dual-stripe mask

shown in Figure 109 has received the most attention The opening between the stripes

ultimately is often the active region of the device Figure 109(a) shows a typical dual

oxide stripe mask pattern on the substrate and Figure 109(b) shows an SAG layer with

enhanced growth in unmasked regions A typical size of the stripe opening required for

the majority of photonic devices is on the order of a few micrometers which is generally

much smaller than the effective vapor-phase diffusion lengths in the growth process

This results in the growth inside the stripe opening being essentially uniform

The growth profile can be modified by varying the width of the mask stripes Varying

the width of the stripes changes the gas-phase density of the precursors in the window

region of the mask A larger mask width results in greater thickness in the grown layer

and vice versa The effect of the mask can be seen easily by looking at GRE profile as a

function of distance Figure 1010 shows simulated and measured GRE profiles of binary

compounds for a dual oxide stripe mask with two different oxide stripe widths The

dielectric layer on the substrate is patterned with a 30-mm window width and 80- and

120-mm mask stripe widths The samples were grown at 650 C and 150 mbar The GRE

in the window regions is larger for the 120-mm mask width than 80 mm for all

compounds

The maximum GRE in the window region varies for each individual binary compound

because the diffusion length at a given temperature varies with choice of precursor For

example the diffusion length at the growth condition of 650 C and 150 mbar was found

to be 50 mm for Al 85 mm for Ga and 10 mm for In

1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting

FIGURE 1010 Simulated and measured growth rate enhancement profiles of binary compounds (AlAs GaAs InP)for a dual-stripe mask with a window width of 30 mm and mask stripe widths of 80 and 120 mm The samples weregrown at a growth temperature of 650 C and a growth pressure of 150 mbar [100] Vapor phase diffusion (VPD)


The adjustment of the GRE in the window region by varying the mask width is also

applicable to ternary and quaternary compounds Figure 106 shows simulated and

measured GRE profiles for AlGaAs InAlAs and AlGaInAs The masks on the substrate

were patterned with a window width of 30 mm and mask stripe widths of 80 and 120 mm

As shown in Table 103 each precursor in the ternary and the quaternary compounds

has a different diffusion length which makes the GRE profile different from the binary

compounds This can be seen in the 30-mm window region of the AlGaAs GRE profile in

Figure 106 The AlGaAs GRE peaks of both simulated and measured plots fall between

the GaAs and AlAs GRE peaks shown in Figure 1010 In addition the difference in

diffusion length creates a variation in the composition along the window region

Figures 1010 and 106 illustrate how the GRE profile changes for a 80- and a 120-mm

mask width Figure 1011 shows the GRE of InP at the center of the window as a function

of the mask width for 10 20 40 and 60 mm window stripe widths The samples were

grown at 630 C and 101 mbar and the extracted value of the diffusion length for this

growth condition is 40 mm The magnitude of GRE increases monotonically with the

mask stripe width largely because of increased net gas-phase diffusion away from the

masked regions In addition the slope of GRE decreases as the width of the window

increases This can be understood from the law of conservation of mass The additional

growth within the window comes from the materials that originate over the mask area

and diffuse laterally to the window region For a given mask width the total amount of

material that can contribute to growth enhancement is the same under similar growth

conditions and is independent of window size For a larger window size the same

amount of material is distributed over a larger area This effect results in a smaller

28

26

24

22

2

18

16

10 10 20 30 40

Mask width (μm)50 60 70 80

12

14Gro

wth

rate

enh

ance

men

t

Ridge width = 10 μm 20 μm

40 μm

60 μm

FIGURE 1011 Simulated and measured InPgrowth rate enhancement profiles at thecenter of different window widths (10 2040 and 60 mm) as a function of the stripewidth of the mask The samples were grownat 630 C and 101 mbar [104]


amount of extra material being deposited at the center of the window and hence a lower

GRE for a larger window size which translates into a decreased slope of GRE versus mask

width for larger window size as shown in Figure 1011

Figure 1012(a) shows the GRE profile of InGaAs measured at the center of the win-

dow as a function of the stripe width of the mask with window widths of 10 20 40 and

60 mm The samples were grown at 630 C and 101 mbar The extracted value of the

effective diffusion length of the precursors at these growth conditions is 36 mm for In and

96 mm for Ga Similar to the InP GRE profile shown in Figure 1011 the simulated and

measured magnitude of GRE at the center of the window increases monotonically with

the mask width and the slope of GRE decreases as the width of the window increases

Figure 1012(b) shows the Ga composition in InGaAs at the center of the window as a

function of the mask width with window widths of 20 40 and 60 mm The Ga compo-

sition decreases as the width of the mask increases The slope of this curve is negative

and it increases as the window width increases

The composition variation is a result of different diffusion lengths for different alloy

constituent precursors The difference in diffusion length changes the ratio of the con-

centration of the two metalndashorganic constituents along the width of the window which

in turn changes the composition profile As explained earlier growth enhancement is a

result of the increased concentration of a precursor compared with the maskless case

Because In has a smaller diffusion length than Ga the concentration of In at the center of

the window increases as the window size decreases As a result the ratio of the con-

centrations of Ga and In decreases accordingly This effect is illustrated by the vertical

change of the curves in Figure 1012(b) On the other hand for a given window size if the

mask width increases the increase in GRE of In is greater than that of Ga as illustrated in

Figure 1010 This explains the lateral variation of Ga composition as a function of the

mask width in Figure 1012(b)

24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t

Ridge width = 10 microm

20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)

FIGURE 1012 (a) InGaAs growth rateenhancement profile (b) Ga Compositionvariation profile at the center of differentwindow widths (10 20 40 and 60 mm)depending on the mask width The samples weregrown at 630 C and 101 mbar [104]


1024 SAG in MBE

MBE systems require an ultra-high vacuum environment which reduces carbon

contamination in the reaction chamber and can result in extremely high purity of the

grown crystal It is often integrated with an in situ growth monitoring system to allow

accurate control of the thickness of each crystal layer with atomic layer interfaces SAG

on a patterned oxide mask using MBE was first introduced by Cho and Ballamy in 1975

[117] They deposited GaAs on a semi-insulating GaAs substrate covered with patterned

SiO2 They observed that the crystal deposited in the window region was monocrystalline

whereas it was polycrystalline on the mask Many efforts were devoted to understanding

the detailed process of polycrystalline formation and to find ways to minimize it It was

found that the polycrystalline deposition on the mask could be reduced by changing the

growth temperature to between 700 C and 775 C [118] In addition reducing the

growth rate showed increased selectivity [118ndash120] SAG in MBE with different types of


precursors has been demonstrated by several groups [118ndash124] It was found that the

selectivity of In compounds is greater than for Ga and Al compounds [118120122] SAG

of InAs by MBE was reported by Okamoto in 1993 [123] He estimated the surface

diffusion length of the precursor by counting the number of atoms in the polycrystalline

material formed on the mask

As mentioned earlier the surface diffusion process dominates selective growth in

MBE This process is similar to the one found in MOCVD The surface diffusion length

can be estimated by counting the density of polycrystals in the mask region if one as-

sumes that polycrystalline deposition on the mask is proportional to the number of

atoms reaching the mask [122] A simple model describing the surface diffusion process

in MBE is shown in Eqn (1024)dn

dtfrac14 D

d2n

dx2thorn R n

s(1024)

where n is the density of the polycrystals on the dielectric mask D is the diffusion

coefficient x is the distance from the edge of the dielectric mask R is the flux of the

precursor and s is the surface lifetime of the precursor

The last term on the right-hand side of Eqn (1024) represents how long the precursor

is able to move freely on the surface before it is incorporated on the surface The surface

diffusion length and geometry of the mask are the only factors that decide selectivity in

MBE If the surface diffusion length of a precursor is large the precursor initially

reaching the mask has a greater probability for diffusing to the window region and

contributing to single crystal growth Conversely if the surface diffusion length is

small the precursor may not have enough time to reach the window area before it is

incorporated which results in polycrystalline formation on the mask

The steady-state concentration can be solved by setting left-hand side of Eqn (1024)

to zero and then using the boundary conditions dndxfrac14 0 at xfrac14 0 and nfrac14 n0 at xfrac14N

Compared with SAG in MOCVD it is difficult to estimate the growth profile in the

window region because the polycrystalline material formed randomly on the mask may

act as a diffusion barrier for the precursors which in turn results in nonuniform

deposition of the precursors in the window

Two factors are believed to contribute to polycrystalline formation in MBE The first is

the growth environment of the MBE system The ultra-high vacuum environment in

MBE precludes any vapor-phase diffusion and makes surface diffusion the sole process

contributing to SAG Unlike MOCVD in which both vapor-phase diffusion and surface

diffusion act together to minimize the parasitic growth on the mask region as discussed

in Section 1022 the absence of vapor-phase diffusion in MBE makes it difficult to

optimize the growth conditions to prevent polycrystalline formation on the mask The

second is the low selectivity resulting from the high sticking probability of the elemental

sources in MBE In MOCVD the absorbed precursors may be desorbed and then diffuse

to the window region On the contrary absorbed group precursors have a much

lower probability of desorption in MBE The nondesorbed precursors contribute to

polycrystalline growth on the mask


Throughout the years a number of MBE-related technologies have been developed to

improve SAG quality SAG using electronndashcyclotronndashresonance plasma-excited MBE was

reported by Yamamoto et al in 1991 [125] GaAs SAG using excited hydrogen-assisted

MBE was reported by Sugaya et al in 1992 [126] GaAs AlAs and AlGaAs SAG using

periodic supply epitaxy by MBE was done by Nishinaga and Bacchin in 2000 [127] SAG

GaN NWs grown by radiofrequencyndashplasma-assisted MBE were reported by Schumann

et al in 2011 [128] Even with these improvements the selectivity in MBE is still not

comparable with MOCVD

103 Applications of Selective Area Masked GrowthIn the previous section we introduced the theoretical model developed by Gibbon et al

[12] that predicts GRE accurately within the window area of the insulating mask using

MOCVD Numerically simulation is generally necessary when it comes to designing a

device with a desired band structure After we have the design tool we are ready to use

SAG for a broad range of advanced photonic applications In this section we provide

three examples to illustrate how SAG can be used to fabricate an integrated optoelec-

tronic system to create an advanced material and to incorporate different material

systems together to achieve enhanced performance

1031 Monolithically Integrated Dual-Wavelength SourceElectroabsorption Modulators and Y-Junction Coupler

The fundamental building blocks of an optoelectronic system generally include the light

source the modulator the light transmission media the switchescombiners and the

detector Each of these building blocks or modules has its own specific requirements for

band structure composition and feature size among other important physical prop-

erties Because of the flexibility in SAG it is possible to integrate them monolithically on

a single substrate In the following example we demonstrate the integration of a light

source modulator combiner and waveguide [50]

Dual-wavelength light sources are important for applications such as wavelength

division multiplexing-based optical communication system color laser printing and

remote sensing by differential absorption It is preferable to build such a dual-

wavelength source monolithically and to use a single output port for both wavelengths

to overcome the practical limitations in alignment of the final system

The design of this light source is shown schematically in Figure 1013 The two laser

emitters connected to the two input ports of the Y-junction coupler both consist of a gain

section and an electroabsorption (EA) modulator section This design allows the two

emitters to operate independently because the modulator sections also aid in avoiding

optical crosstalk between emitters The length of the gain and the modulator sections for

each arm is 800 and 400 mm respectively The selectively grown thickness of the gain

section in each emitter is different which leads to a different emission wavelength for

Channels1 and 2

Gainsection Modulator

section Y-junctionsection

GaAsnsubstrate

Active layerAl06Ga04Asn

Al06Ga04AsnGaAsp cap

FIGURE 1013 Three-dimensional illustration of a dual-wavelength laser system The cross-section shows the thick-ness of the InGaAs active layer varies in different sections of the device (not drawn to scale)


each individual emitter The thickness of the modulator section in each arm is designed

to be slightly smaller than that of its corresponding gain section As a result the lowest

order optical transition of the modulator section is slightly blue shifted with respect to

that of the gain section which ensures the light generated in the gain section is trans-

parent to the corresponding unbiased modulator in the same arm The quantum-

confined Stark effect is used to shift the absorption edge of the modulator into the

lasing wavelength of the gains section to introduce a voltage-controlled loss in the cavity

The passive Y-junction coupler is designed to have an even thinner QW layer than the

gain and the modulator sections of both arms so it will be transparent to the light

generated in either of them All the elements of this device use a BH configuration with

the same width of 4 mm to provide strong lateral confinement of the light The radius of

curvature of the Y-junction s-bends is 400 mm It is very large compared with the two

laser wavelengths so that the bending loss of the Y-junction is small From Figure 1013

we can see that there is a 50-mm-long 07-mm-deep trench in the GaAs cap layer sepa-

rating the gain section and the modulator section which provides electrical isolation

between them Another deeper trench exists between the two arms to give a 75-kU

resistance Separate p-contact metal pads are used for each individual section The

single arm end of the Y-junction is curved to minimize the back reflection from the

cleaved output edge which may induce undesired instability to the device

To fabricate such a device successfully the key challenge is to control the thickness of

the QW layer accurately in each section The dual-stripe mask introduced in the previous

section is used experimentally to define the width of the BH As pointed out earlier the

width of all BH elements is the same The variation of the QW thickness is achieved by

changing the width of the insulating mask stripes Figure 1014 shows a microscope

image of the optical mask used in fabricating this device In Figure 1014 areas in bright

yellow represent the region that eventually transfers to the substrate as the insulating

Gain sectionGain section

Modulatorsection

Modulatorsection

Y-junction couplerY-junction coupler

Output waveguideOutput waveguide

Channel 1

Channel 2

FIGURE 1014 Microscope image of the E-beam mask used to fabricate the dual-wavelength laser source Areas inbright yellow represent the region that eventually transfers to the substrate as the insulating dielectric growthmask for selective area epitaxy Different widths of each section determine the final thickness of thecorresponding active layer


dielectric growth mask for SAE The widths of the growth mask for channel 1 are 4 mm in

the gain section and 26 mm in the modulator The widths for channel 2 are 6 mm in the

gain section and 4 mm in the modulator section The growth mask width for the

Y-junction coupler is 2 mm for both channels In the final device the emission wave-

lengths of channel 1 are 1045 mm for the gain section and 1025 mm for the modulator

section Similarly emission wavelengths of the gain and the modulator sections in

channel 2 are 1017 and 1001 mm respectively

The device was grown by conventional atmospheric pressure MOCVD in a vertical

reactor configuration using a three-step growth process The first growth in the three-

step sequence consists of a GaAs buffer layer a lower AlGaAs cladding layer and

15 nm of the GaAs barrier to prevent oxidation of the AlGaAs when the sample is

removed from the reactor Next an oxide is deposited on the wafer and the selective

mask pattern is transferred using standard photolithographic techniques After

patterning the sample is returned to the reactor for growth of the InGaAsndashGaAs active

region After this step the wafer is again removed from the reactor and the oxide is

etched away in a buffered HF solution Last the sample is returned to the reactor for

growth of the upper cladding and contact layers


To check the performance of the finished device we measured the optical power

versus the injection current and the output spectra of the device under different oper-

ating conditions Figure 1015 shows the dependence of continuous-wave (CW) output

power as a function of current (LndashI characteristic) for the two channels biased inde-

pendently Channel 1 has a threshold current of 95 mA and the threshold current for

channel 2 is 101 mA The inset in Figure 1015 shows the CW spectra of the longitudinal

mode from the same device under three different operating conditions The injection

current applied to the active layer of each channel is 15 mA for all three measurements

Output light was coupled into a single mode fiber and the spectra was measured using

an optical spectral analyzer When no bias was applied to both channels we obtained an

output spectrum that showed two peaks centered at the two designed emission wave-

lengths as shown in the lower spectrum in the inset of Figure 1015 When a modulator

bias of 2 V was applied to either one of the channels as shown in the top two spectra in

Figure 1015 the EA operates to extinguish the light emission from that channel We

observed a slight red shift of the peak emission wavelength in the uppermost spectrum

as a result of junction heating from the photogenerated current The spectral distance

between the two emission peaks is determined by the relative thickness of the active

regions of both channels and in turn is controlled by the dimension of the oxide mask

used to define the active regions in MOCVD growth For this particular device design the

spectral distance is 28 nm The modulator section of channel 1 has a smaller bandgap

compared with that of the active region of channel 2 As a result the modulator of

channel 1 is absorbing the light generated in channel 2 even without any bias This

5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0

101 103 107105Wavelength (microm)

FIGURE 1015 LndashI characteristics for a dual-channel source operating in a continuous wave at room temperatureThe threshold current for channel 1 (channel 2) is 95 mA (101 mA) The inset shows the longitudinal modespectra for the two channels biased simultaneously at 15 mA with the indicated voltage applied to themodulator sections


explains why one does not observe the higher energy device (channel 2) pumping the

lower energy device (channel 1) beyond the threshold over the entire range of current

shown in Figure 1015 even when both modulator sections were left unbiased [50]

1032 Inverse Quantum Dot Array

The QW laser has become the standard semiconductor laser structure because of its

continuous advances in epitaxial techniques that allow controlled growth at an atomic

scale Higher order quantum confinement in the lateral domain is desirable because it

may offer narrower spectral linewidth and greater temperature stability and requires a

lower threshold current Both self-assembly and SAG have been used successfully to

build QD lasers Compared with self-assembled QDs patterned QDs fabricated using

SAG generally exhibit better defined dot size and long-range periodicity of the dot array

in the lateral dimensions However the areal fill actor of the QD laser is less than that of

the QW As a result the achievable gain volume is decreased significantly To overcome

this issue a novel structure similar to patterned QDs called the IQDA has been pro-

posed [656673129] The IQDA is a periodically perforated QW in which the voids are

filled with higher energy bandgap materials as shown in Figure 1016 This structure is

an electronic analog of a photonic crystal Lasers with IQDA as the active layer were first

fabricated using SAG which is the focus of this section

The base structure growth for the IQDA was performed in an atmospheric pressure

MOCVD reactor The base structure serves as the bottom half of a separate confinement

heterostructure It consists of a 100-nm GaAs buffer layer grown on a (100) GaAs wafer

followed by the growth of a 1-mm n-type Al075Ga025As lower cladding and 100-nm

intrinsic GaAs lower core After the base structure is grown hydrogen silsesquioxane

(HSQ) is spun on the wafer and electron-beam lithography is performed The pattern

consists of an array of points on a hexagonal lattice with an 80-nm center-to-center

pitch HSQ becomes silicon dioxide in the areas where it was written by the beam and

acts as the SAGmask in the subsequent regrowth step Unwritten HSQ is developed away

using a solution of tetramethylammonium hydroxide which leaves an array of silicon

GaAs Barrier

GaAsBarrier

InxGa1ndashxASGaAsActive region

FIGURE 1016 3D illustration of the inverse quantum dot array structure showing the perforation in thequantum well


dioxide dots of approximately 40 nm in diameter on the surface The sample is then

returned to the reactor for the growth of an 8-nm-thick layer of In025Ga075As and a

10-nm-thick GaAs cap which forms the IQDA active layer in the patterned regions and

an ordinary QW elsewhere The silicon dioxide growth mask is then removed using a

buffered hydrofluoric acid solution and the sample is returned to the reactor for the

growth of the upper barrier This regrowth consists of a 90-nm-thick layer of intrinsic

GaAs Next 4-mm-wide ridges are etched over the IQDA regions to act as a lateral

waveguide for the completed devices Last a third regrowth step is performed

that consists of a 10-nm-thick layer of intrinsic GaAs to complete the upper barrier a

1-mm-thick layer of p-type Al075Ga025As to provide the upper cladding and a

100-nm-thick GaAs p-contact layer

Finally stripe geometry diode lasers are processed in the usual manner [65130] In

addition to the devices containing an IQDA active layer devices from unpatterned re-

gions of the sample are fabricated as well These devices contain an ordinary QW well

active layer and are used as control devices for comparison with the IQDA lasers

Figure 1017 shows the electroluminescence spectra of the IQDA laser and the QW

control device under identical injection conditions at 77 K Compared with the single

emission peak spectrum from the QW laser there is an obvious gap between the two

emission peaks from the IQDA laser which arises from an intraband forbidden energy

gap that exists in the IQDA structure A theoretical model based on Schrodingerrsquos

equation with a periodically perturbed energy potential barrier was developed to

investigate the energy band structure of the IQDA [129] Both partial function expansion

and finite difference analysis have been used to obtain the wave function and the energy

band structure of the IQDA The main results from the numerical simulation are sum-

marized in Figure 1018 Energy subbands were formed in both conduction and valance

Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA

FIGURE 1017 Electroluminescence spectra of the inverse quantum dot array (IQDA) and the quantum well lasersat 77 K arb arbitrary

8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)

FIGURE 1018 (a b) Theoretically calculated joint density of states of the contribution from the first three inversequantum dot array subbands (a) and the gain spectrum at a 90-mA injection current (b) arb arbitrary


bands of the original QW structure A selection rule determining the allowed transition

between these subbands is that only those transitions between like-numbered subbands

are allowed For example there is allowed transition from the first subband in the

conduction band to the first subband in the valance band but the transition from the

second subband in the conduction band to the first subband of the valance band is

forbidden The joint density of states taking into account the interband selection rules is

shown in Figure 1018(a) The calculated gain spectrum is shown in Figure 1018(b)

From these simulation results the broad peak centered at 963 nm can be attributed to

the overlap of the first and the second intersubband transitions The peak generated by

the first intersubband transition is higher than that of the second one As a result the

latter appears as a shoulder on the former in the calculated spectrum The peak at

959 nm comes from the transition between the third intersubband transition Because

both subbands exhibit a delta functionlike density of state the spectral width of this peak

is considerably narrower than the previous two This result is in excellent agreement with

the experimentally obtained spectrum at an injection current of 90 mA

The unique structure of the IQDA allows the active layer to be tuned to exhibit either

QD-like or QW-like physical properties When the diameter of the perforated holes d is

large compared with the lattice constant of the IQDA array a (ie da is close to one)

the carriers in the active layer are confined more to the region between the periodic GaAs

barriers In the extreme case when da is 1 the structure actually becomes a QD array

in which carriers are confined in the isolated periodic islands On the other hand if

da laquo 1 the carriers in the active layer can move almost freely within the lateral plane and

the structure approaches the original QW with weak periodic perturbation This feature

provides an additional design freedom to tailor the physical properties according to

particular application needs Preliminary experimental results show that the IQDA may

generate greater photocurrent density compared with the QW with the same thickness of

active layer It is conceivable that by adjusting the da ratio one can find an optimum

structure that may have greater light conversion efficiency for solar energy harvesting

Research of the IQDA is still in the infant stage The quality and uniformity of the IQDA


can be expected to improve as lithography etching and epitaxial growth technologies

progress Potential applications using the IQDA as the active layer are yet to be explored

fully

1033 IIIndashV NWs on a Silicon Substrate

IIIndashV compound semiconductors are the material of choice for most optoelectronic

applications because of their direct bandgap energy band structure and hence higher

light generation efficiency than silicon On the other hand silicon has dominated

electronic applications for half a century Since early 2003 silicon photonic devices and

systems have attracted a lot attention because of their compatibility with traditional

CMOS electronics [131ndash142] However an electronically pumped silicon light source is

still unavailable A promising solution to this problem is to integrate a IIIndashV light source

on a silicon substrate which has been a challenge since the 1980s The main technical

obstacles for this heteroepitaxy include the mismatch in both lattice constant and

thermal expansion coefficients the presence of a polarndashnonpolar interface that leads to

high dislocation density in the IIIndashV materials and the unintentional doping of the IIIndashV

NWs from the silicon substrate In 2004 Martensson et al [143] grew GaP NWs suc-

cessfully with optically active GaAsxP1x heterostructure segments on a silicon substrate

Since then efforts from many research groups have expanded the IIIndashV NW material

systems to GaAs InP InAs GaSb and some ternary alloys [144] The small diameter of

NWs essentially makes them a one-dimensional electron system that has the potential to

serve as the building block of next-generation electronic and photonic devices

SAG has been used to grow GaAsAlGaAs corendashshell NWs on a silicon (111) substrate

LEDs based on this structure have been demonstrated by Fukui and others [145ndash149]

For NW-based devices position control is of great importance because it helps to orient

NW growth direction and to achieve high-density integration In addition as discussed

later the size of the opening window is critical for growing uniformly vertical IIIndashV NWs

on a silicon substrate SAG is very suitable for providing the position and window size

control necessary for high-quality NWs

GaAs crystals have a zinc blende structure It grows preferentially along the lt111gtA

(outmost atomic layers contains group III atoms) direction or the lt111gtB (outmost

atomic layers contains group V atoms) direction For a silicon substrate there is no

distinction between the (111)A and (111)B planes Therefore NW growth along the four

equivalent lt111gt directions always occurs on a silicon (111) surface To achieve vertical

growth of GaAs NWs on a silicon (111) substrate initial surface optimization processes

were undertaken to reconstruct the surface and to remove the native oxide on it

n-Type (111)-oriented silicon substrates were used as starting substrates First the

substrates were treated chemically to remove metal particles from their surfaces Then

20-nm-thick SiO2 was formed by using a thermal oxidation process at 950 C which

helps to avoid heat shrinkage of the SiO2 template E-beam lithography was used to form

the openings in the mask where the GaAs NWs can grow Then in situ thermal cleaning


was carried out at 925C The in situ thermal cleaning was used to remove native oxides

from the opening regions The substrate then went through a high-temperature

annealing process cooling to 400C in a hydrogen ambient followed by AsH3 treat-

ment to form the As-adsorbed silicon (111) surface Next a thin GaAs low-temperature

buffer layer was grown to prevent thermal desorption of As atoms from the silicon

substrate After these steps GaAs NWs could grow vertically along the (111) direction on

the silicon substrate using a low-pressure MOCVD system as shown in Figure 1019

GaAs growing along the lt111gtB direction exhibits threefold symmetry As a result

nucleation of GaAs starts from forming isolated triangular 2D islands on the (111)B

surface As these islands grow bigger they coalesce with adjacent ones and result in

some unexpected facets formed on the final structure This is the case when GaAs grows

on an unmasked silicon substrate It was found experimentally that when the size of the

opening on the mask is large (ie the diameter of the opening is greater than a few

hundreds of nanometers) similar hillocklike structures were formed within the opening

However if the opening diameter is decreased to less than 100 nm this effect was

suppressed completely This is confirmed by both scanning electron micrograph images

and microphotoluminescence measurements

After the GaAs NWs are grown it is possible to grow a IIIndashV heterostructure radially to

form a corendashshell structure This control of the growth direction of SAG is achieved by

adjusting the growth temperature during MOCVD processes To grow an AlGaAs shell on

GaAs NWs the partial pressure of the total group III precursors and the AsH3 were kept

the same but the temperature was increased from 750C for GaAs growth to 850C for

AlGaAs growth The lateral growth of AlGaAs on the sidewall of GaAs NWs is a result of

the strong bonding and the lower migration length of Al atoms along the 110 surfaces of

FIGURE 1019 Scanning electron micrograph image of a GaAs nanowire array on a silicon (111) surface [148]

(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT

13 14 15 16 17 18Photon energy (eV)

400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT

FIGURE 1020 (a) Structure of the corendashmultishell nanowire (b) Electroluminescence (EL) measurements of thecorendashmultishell nanowire under different injection currents arb arbitrary RT room temperature


GaAs which is perpendicular to the GaAs NW growth direction of [111]B The AlGaAs

shell grown on the GaAs NW core may act as in situ passivation against surface states of

GaAs to achieve dramatically enhanced photoluminescence intensity [145148]

Furthermore a more sophisticated corendashmultishell structure based on this technol-

ogy has been demonstrated to integrate IIIndashV NW-based LEDs directly on a silicon

substrate Figure 1020(a) illustrates the structure of an individual corendashmultishell NW

The core of the NW is an n-type GaAs 100 nm in diameter grown selectively on a silicon

(111) substrate The innermost shell is a 25-nm-thick n-AlGaAs It is followed by a

10-nm-thick p-GaAs QW layer a 25-nm-thick p-AlGaAs and finally another 10-nm-thick

p-GaAs capping layer This forms a radially orientated double heterostructure After

depositing a metal contact connecting the outmost shell and mechanical polishing to

remove the metal on the top of the NW the resulting device is an array of NW-based

LEDs on a silicon substrate Because of the large surface-to-volume ratio intrinsic to

the NW structure this radial pndashn junction design is more area efficient which may lead

to enhanced performance in light emission Another advantage of this design is that the

silicon substrate can act as a heat sink to stabilize the operating temperature of the LED

Electroluminescence experiments using this device demonstrated that the peak of the

emission spectrum did not shift with increased injection current

104 SummaryIn this chapter we introduced the SAG technique using an insulating mask to provide 3D

control of both the structure and the composition of semiconductor devices with

extremely high accuracy This allows for the integration of a large quantity of

such devices on a single substrate to build sophisticated on-chip electronic andor

optoelectronic systems with greatly enhanced performance and stability


There are three different growth modes Semiconductor crystals grow in one of them

depending on the surface mismatch and the thickness of the final strain layer It is

important to understand the growth mode to design a suitable SAG structure of certain

material on a given substrate

MOCVD was chosen to be the exemplary growth system because it is possible to

achieve high selectivity with it and it is versatile in the materials suitable for it to grow

Many factors of the growth condition in MOCVD contribute to its selectivity including

growth temperature growth pressure and partial pressure of the precursors All of these

factors can be controlled outside the growth chamber

Two diffusion processes work together to determine the growth enhancement effect

and the composition variation in the SA-MOCVD system near the boundary of the mask

vapor-phase diffusion and surface diffusion The theoretical model developed by Gibbon

et al [12] includes both and is widely used to predict the final growth profile accurately

in the active region This model was introduced in detail and applied to a simple dual-

stripe mask configuration in Section 1022 When the spacing between the two mask

stripes is much smaller than the effective diffusion length of the precursors highly

uniform crystal growth takes place in the window between those stripes GRE increases

with stripe width These features can be used in high-performance optoelectronic device

design Experimental results shown in Section 1023 confirm the validity of the model

We briefly covered SAG in MBE and compare it with SA-MOCVD in Section 1024

Although MBE is a powerful growth tool it is relatively difficult to achieve the same level

of selectivity with it compared with the selectivity in SA-MOCVD In addition poly-

crystalline material usually forms on the mask during SAG in MBE This is because the

vapor-phase diffusion process does not exist in MBE and the elemental material used in

MBE has a high sticking probability to the substrate The polycrystalline material affects

adversely the uniformity of the selectively grown device How to avoid it and to achieve

greater selectivity in MBE are the major challenges of SAG in MBE

SA-MOCVD can be used in a broad range of applications We presented three

examples in Section 103 to illustrate the power of SA-MOCVD The first example was

integrated optoelectronic system growth by SA-MOCVD consisting of two lasers two EA

modulators a Y-branch combiner and an output waveguide This example demon-

strated how to use SAG to integrate multiple devices on the same substrate and to grow

them simultaneously to achieve greater performance The second example involved a

novel material IQDA created by SA-MOCVD IQDA is a periodically perforated InGaAs

QW with holes filled by selectively grown GaAs which has larger bandgap than InGaAs

and serves as periodic higher energy barriers within the lateral plane of the active region

of the QW It introduces distinct subband modification to both the valance and the

conduction bands of the QW Both simulation and experimental results confirmed the

formation of the subband Lasers using IQDA as the active media have been demon-

strated experimentally The last example was the hybrid integration of IIIndashV NWs onto a

silicon substrate The selectively grown multiple corendashshell NW array was used as the

light-emitting element with enhanced area efficiency and light-emitting performance


SAG provides a promising and elegant solution to the increasing demands from and

challenges of high-performance highly integrated electronic and optoelectronic sys-

tems It is conceivable that it will continue to play an important role in the design and

fabrication of the next-generation very-large-scale integrated circuit and photonic

integration circuit

AcknowledgmentsThe authors thank Mr Pavel Liudvih for preparing Figures 1013 and 1014 and for his help in collecting

some of the references

References[1] Davies GJ Duncan WJ Skevington PJ French CL Foord JS Selective area growth for opto-

electronic integrated circuits (OEICs) Materials Science and Engineering B 15 July 19919(1ndash3)93ndash100

[2] Yi SS Kuech TF Selective Area Epitaxy on Structures and Surfaces Invited Encyclopedia Article inEncyclopedia of Materials Amsterdam Science and Technology Elsevier 2001 p 8295ndash9

[3] Coleman JJ Metalorganic chemical vapor deposition for optoelectronic devices Proc IEEE 199785(11)1715ndash29

[4] Kuech TF The use of chloride based precursors in metalorganic vapor-phase epitaxy J CrystGrowth 1991115(1ndash4)52ndash60

[5] Kuech TF Tischler MA Potemski R Selective epitaxy in the conventional metalorganic vaporphase epitaxy of GaAs Appl Phys Lett 198954(10)910ndash2

[6] Yamaguchi K Okamoto K Selective epitaxial-growth of AlGaAs by atmospheric-pressure ndashMOCVD using diethylgalliumchloride and diethylaluminiumchloride Jpn J Appl Phys Part 1 199029(8)1408ndash14

[7] Secrest BG Boyd WW Shaw DW Application of finite element method to mass transport limitedepitaxial growth processes J Cryst Growth 197110(3)251ndash9

[8] Seki H Koukitu A Thermodynamic analysis of metalorganic vapor phase epitaxy of IIIndashV alloysemiconductors J Cryst Growth 198674(1)172ndash80

[9] Omstead TR Jensen KF Kinetic-model for metal organic-chemical vapor-deposition of GaAs withorganometallic arsenic precursors Chem Mater 19902(1)39ndash49

[10] Yamaguchi K-i Okamoto K Analysis of deposition selectivity in selective epitaxy of GaAs bymetalorganic chemical vapor deposition Jpn J Appl Phys 199029(Part 1 No 11)2351ndash7

[11] Yamaguchi K-i Ogasawara M Okamoto K Surface-diffusion model in selective metalorganicchemical vapor deposition J Appl Phys 199272(12)

[12] Gibbon M Stagg JP Cureton CG Thrush EJ Jones CJ Mallard RE et al Selective-area low-pressureMOCVD of GaInAsP and related materials on planar InP substrates Semicond Sci Technol 19938(6)998

[13] Zybura MF Jones SH A simplified model describing enhanced growth-rates during vapor-phaseselective epitaxy J Electron Mater 199423(10)1055ndash9

[14] Korgel B Hicks RF A diffusion model for selective-area epitaxy by metalorganic chemical vapordeposition J Cryst Growth 1995151(1ndash2)204ndash12


[15] Mircea A Jahan D Ougazzaden A Delprat D Silvestre L Zimmermann G Manolescu AManolescu AM Computer modelling of selective area epitaxy with organometallics InSemiconductor conference 1996 International vol 2 1996 pp 625ndash8 vol2 9ndash12 Oct 1996

[16] Coleman JJ Lammert RM Osowski ML Jones AM Progress in InGaAs-GaAs selective-areaMOCVD toward photonic integrated circuits IEEE J Sel Top Quantum Electron 19973(3)874ndash84

[17] Rondanini M Cavallotti C Moscatelli D Masi M Carra S A combined fluid dynamic and 3D ki-netic Monte Carlo investigation of the selective deposition of GaAs and InP J Cryst Growth 2004272(1ndash4)52ndash8

[18] Dupuis N Decobert J Lagree PY Lagay N Cuisin C Poingt F et al AlGaInAs selective area growthby LP-MOVPE experimental characterisation and predictive modelling Optoelectron IEE Proc2006153(6)276ndash9

[19] Wang Y Song Y Sugiyama M Nakano Y Shimogaki Y Nonlinear kinetic analysis of InP and InAsmetal organic vapor phase epitaxy by selective area growth technique Jpn J Appl Phys 200847(11)8269ndash74

[20] Cockerill TM Forbes DV Dantzig JA Coleman JJ Strained-layer InGaAs GaAs AlGaAs buried-heterostructure quantum-well lasers by 3-step selective-area metalorganic chemical-vapor-deposition IEEE J Quantum Electron 199430(2)441ndash5

[21] Nall JR Lathrop JW The fabrication and packaging of semiconductor devices by photolithographictechniques In International conference on solid state physics and its application to electronicsand telecommunications 1958 Brussels

[22] Liimatainen TM Recent advances in the application of photo-lithographic techniques to semi-conductor devices and microminiaturization Proc IEE ndash Part B 1959106(15)385ndash90

[23] Joyce BD Baldrey JA Selective epitaxial deposition of silicon Nature 1962195(4840)485ndash6

[24] Tausch FW Lapierre AG A novel crystal growth phenomenon ndash single crystal GaAs overgrowthonto silicon dioxide J Electrochem Soc 1965112(7)706ndash9

[25] Shaw DW Selective epitaxial deposition of gallium arsenide in holes J Electrochem Soc 1966113(9)904ndash8

[26] Manasevit HM Simpson WI Use of metal-organics in preparation of semiconductor materials IEpitaxial gallium-V compounds J Electrochem Soc 1969116(12)1725ndash32

[27] Manasevit HM Simpson WI Use of metal-organics in preparation of semiconductor materials IIIIndashVI compounds J Electrochem Soc 1971118(4)644ndash7

[28] Manasevit HM Use of metal-organics in preparation of semiconductor materials III Studies ofepitaxial III-V aluminum compound formation using trimethylaluminum J Electrochem Soc 1971118(4)647ndash50

[29] Manasevit HM Erdmann FM Simpson WI Use of metalorganics in preparation of semiconductormaterials IV Nitrides of aluminum and gallium J Electrochem Soc 1971118(11)1864ndash8

[30] Ghosh C Layman RL Selective area growth of gallium-arsenide by metalorganic vapor-phaseepitaxy Appl Phys Lett 198445(11)1229ndash31

[31] Azoulay R Bouadma N Bouley JC Dugrand L Selective MOCVD epitaxy for optoelectronic de-vices J Cryst Growth 198155(1)229ndash34

[32] Sacilotti M Mircea A Azoulay R Growth of InP by organometallic vapor epitaxy J Cryst Growth198363(1)111ndash5

[33] Kayser O Westphalen R Opitz B Balk P Control of selective area growth of InP J Cryst Growth1991112(1)111ndash22


[34] Kamon K Takagishi S Mori H Selective growth of AlxGa1xAs embedded in etched grooves onGaAs by low-pressure OMVPE J Cryst Growth 198677(1ndash3)297ndash302

[35] Kimura K Takagishi S Horiguchi S Kamon K Mihara M Ishii M Low-pressure OMVPE of GaAsusing triethylgallium Jpn J Appl Phys Part 1 198625(9)1393ndash6

[36] Bhat R Keramidas VG Comparative-study of GaAs grown by organo-metallic chemical vapor-deposition (OMCVD) using trimethyl and triethyl gallium sources Proc Soc Photo-Opt InstrumEng 1982323104ndash9

[37] BhatROMCVDgrowthofGaAsandAlGaAsusinga solid as source J ElectronMater 198514(4)433ndash49

[38] Bhat R Chan WK Kastalsky A Koza MA OMCVD grown high-gain modulation doped AlGaAsGaAs transistors with no IV collapse IEEE Trans Electron Devices 198532(11)2528

[39] Bhat R Koza MA OMCVD growth of GaAs using diethylarsine J Electron Mater 198615(5)293

[40] Bhat R Koza MA Hayes JR A new technique for the growth of compositionally graded layers byOMCVD for novel device structures J Cryst Growth 198677(1ndash3)293ndash6

[41] Galeuchet YD Roentgen P Selective area MOVPE of gain AsInP heterostructures on masked andnonplanar (100) and (111) substrates J Cryst Growth 1991107(1ndash4)147ndash50

[42] Yamaguchi K Ogasawara M Okamoto K Surface-diffusion model in selective metalorganicchemical vapor-deposition J Appl Phys 199272(12)5919ndash25

[43] Kayser O Selective growth of InPGaInAs in LP-MOVPE and MOMBECBE In Metalorganic vaporphase epitaxy 1990 proceedings on metalorganic vapor phase epitaxy and workshop on MOMBECBE GSMBE related techniques vol 107(1ndash4) 1991 pp 989ndash98

[44] Colas E Shahar A Soole BD Tomlinson WJ Hayes JR Caneau C et al Lateral and longitudinalpatterning of semiconductor structures by crystal-growth on nonplanar and dielectric-maskedGaAs substrates ndash application to thickness-modulated wave-guide structures J Cryst Growth1991107(1ndash4)226ndash30

[45] Song H Sugiyama M Nakanoc Y Shimogak Y Nonlinear kinetics of GaAs MOVPE examined byselective area growth technique J Electrochem Soc 2007154(2)H91ndash6

[46] Mori Y Kamada M MOVCD growth of selectively doped AlInAsGaInAs heterostructures J CrystGrowth 198893(1ndash4)892ndash9

[47] Crook AC Cockerill TM Forbes DM Herzinger CM DeTemple CA Coleman JJ Low drive voltageGaAs quantum-well electroabsorption modulators obtained with a displaced junction IEEEPhotonics Technol Lett 19946(5)619ndash22

[48] Lammert RM Forbes DV Smith GM Qsowski ML Coleman JJ InGaAs-GaAs quantum-well laserswith monolithically integrated intracavity electroabsorption modulators by selective-area MOCVDIEEE Photonics Technol Lett 19968(1)78ndash80

[49] Lammert RM Roh SD Hughes JS Osowski ML Coleman JJ MQW DBR lasers with monolithicallyintegrated external-cavity electroabsorption modulators fabricated without modification of theactive region IEEE Photonics Technol Lett 19979(5)566ndash8

[50] Osowski ML Lammert RM Coleman JJ A dual-wavelength source with monolithically integratedelectroabsorption modulators and Y-junction coupler by selective-area MOCVD IEEE PhotonicsTechnol Lett 19979(2)158ndash60

[51] Miller LM Beernink KJ Verdeyen JT Coleman JJ Hughes JS Smith GM et al InGaAs GaAs AlGaAsstrained-layer distributed feedback ridge wave-guide quantum-well heterostructure laser arrayElectron Lett 199127(21)1943ndash5

[52] Miller LM Verdeyen JT Coleman JJ Bryan RP Alwan JJ Beernink KJ et al A distributed feedbackridge wave-guide quantum-well heterostructure laser IEEE Photonics Technol Lett 19913(1)6ndash8


[53] Lammert RM Jones AM Youtsey CT Hughes JS Roh SD Adesida I et al InGaAsP-InP ridge-waveguide DBR lasers with first-order surface gratings fabricated using CAIBE IEEE PhotonicsTechnol Lett 19979(11)1445ndash7

[54] Osowski ML Hughes JS Lammert RM Coleman JJ An asymmetric cladding gain-coupled DFBlaser with oxide defined metal surface grating by MOCVD IEEE Photonics Technol Lett 19979(11)1460ndash2

[55] Osowski ML Panepucci R Adesida I Coleman JJ A strained-layer InGaAs-GaAs asymmetriccladding gain-coupled DFB laser with titanium surface gratings by metalorganic chemical vapordeposition IEEE Photonics Technol Lett 19979(4)422ndash4

[56] Osowski ML Hughes JS Coleman JJ Effect of p-contact metallization on the performance ofgain-coupledDFBrsquoswithoxide-definedsurfacegratings IEEEPhotonicsTechnolLett199810(7)926ndash8

[57] Cockerill TM Forbes DV Han H Coleman JJ Monolithic integration of a strained-layer InGaAs-GaAs-AlGaAs quantum-well laser with a passive wave-guide by selective-area MOCVD IEEEPhotonics Technol Lett 19935(4)448ndash50

[58] Lammert RM Cockerill TM Forbes DV Coleman JJ Dual-channel strained-layer in GaAs-GaAs-AlGaAs WDM source with integrated coupler by selective-area MOCVD IEEE Photonics TechnolLett 19946(10)1167ndash9

[59] Lammert RM Mena PV Forbes DV Osowski ML Kang SM Coleman JJ Strained-layer InGaAs-GaAs-AlGaAs lasers with monolithically integrated photodiodes by selective-area MOCVD IEEEPhotonics Technol Lett 19957(3)247ndash50

[60] Osowski ML Lammert RM Forbes DV Ackley DE Coleman JJ Broad-band emission from InGaAs-GaAs-AlGaAs LED with integrated absorber by selective-area MOCVD Electron Lett 199531(17)1498ndash9

[61] Lammert RM Smith GM Hughes JS Osowski ML Jones AM Coleman JJ MQW wavelength-tunable DBR lasers with monolithically integrated external cavity electroabsorption modulatorswith low-driving-voltages fabricated by selective-area MOCVD IEEE Photonics Technol Lett 19968(6)797ndash9

[62] Roh SD Yeoh TS Swint RB Huber AE Woo CY Hughes JS et al Dual-wavelength InGaAs-GaAsridge waveguide distributed Bragg reflector lasers with tunable mode separation IEEE PhotonicsTechnol Lett 200012(10)1307ndash9

[63] Elarde VC Rangarajan R Borchardt JJ Coleman JJ Room-temperature operation of patternedquantum-dot lasers fabricated by electron beam lithography and selective area metal-organicchemical vapor deposition IEEE Photonics Technol Lett 200517(5)935ndash7

[64] Elarde VC Yeoh TS Rangarajan R Coleman JJ Patterned InGaAs quantum dots by selective areaMOCVD In Compound semiconductors 2004 proceedings vol 184 2005 pp 353ndash9

[65] Elarde VC Coleman JJ A novel ordered nanopore array diode laser IEEE Photonics Technol Lett200820(1ndash4)240ndash2

[66] Verma VB Elarde VC Coleman JJ Low-temperature electroluminescence from an orderednanopore array diode laser Microelectron J 200940(3)584ndash7

[67] Coronell DG Jensen KF Analysis of MOCVD of GaAs on patterned substrates J Cryst Growth 1991114(4)581ndash92

[68] Silvestri VJ Ghez R Sedgwick TO Growth mechanism for germanium deposition near a SiO2-Geboundary J Electrochem Soc 1972119(2)245ndash50

[69] Oldham WG Holmstrom R The growth and etching of Si through windows in SiO2 J ElectrochemSoc 1967114(4)381ndash8

[70] Song HZ Sugiyama M Nakano Y Shimogaki Y Nonlinear kinetics of GaAs MOVPE examined byselective area growth technique J Electrochem Soc 2007154(2)H91ndash6


[71] Zmudzinski CA Zory PS Lim GG Miller LM Beernink KJ Cockerill TL et al Differential gain inbulk and quantum-well diode-lasers IEEE Photonics Technol Lett 199131057ndash60

[72] Bauer E Phanomenologische Theorie der Kristallabscheidung an Oberflachen I Z fur Kristallogr1958110(1ndash6)372ndash94

[73] Coleman JJ Young JD Garg A Semiconductor quantum dot lasers a tutorial J Lightwave Technol201129(4)499ndash510

[74] Frank FC van der Merwe JH One-dimensional dislocations I Static theory Proc R Soc Lond Ser A1949198(1053)205ndash16

[75] Matthews JW Blakeslee AE Defects in epitaxial multilayers I Misfit dislocations J Cryst Growth197427118ndash25

[76] Lammert RM Cockerill TM Forbes DV Smith GM Coleman JJ Submilliampere threshold buried-heterostructure InGaAsGaAs single-quantum-well lasers grown by selective-area epitaxy IEEEPhotonics Technol Lett 19946(9)1073ndash5

[77] Cockerill TM Lammert RM Forbes DV Osowski ML Coleman JJ et al 12-Channel strained-layerInGaAs-GaAs-AlGaAs buried heterostructure quantum-well laser array for WDM applications byselective-are MOCVD IEEE Photonics Technol Lett 19946(7)786ndash8

[78] Yeoh TS Liu CP Swint RB Huber AE Roh SD Woo CY et al Epitaxy of InAs quantum dots on self-organized two-dimensional InAs islands by atmospheric pressure metalorganic chemical vapordeposition Appl Phys Lett 200179(2)221ndash3

[79] Fukui T Ando S Tokura Y Toriyama T GaAs tetrahedral quantum dot structures fabricated usingselective area metalorganic chemical vapor deposition Appl Phys Lett 199158(18)

[80] Elarde VC Yeoh TS Rangarajan R Coleman JJ Controlled fabrication of InGaAs quantum dots byselective area epitaxy MOCVD growth J Cryst Growth 2004272(1ndash4)148ndash53

[81] Miller LM Coleman JJ Metalorganic chemical vapor deposition Crit Rev Solid State Mater Sci198815(1)1ndash26

[82] Dapkus PD Metalorganic chemical vapor deposition Annu Rev Mater Sci 198212(1)243ndash69

[83] Stringfellow GB Organometallic vapor-phase epitaxy theory and practice Academic Press 1999

[84] Deposition precursor products SAFC 2013

[85] Rosenbaum EJ Sandberg CR Vapor pressures of trimethylphosphine trimethylarsine andtrimethylstibine J Am Chem Soc 194062(6)1622ndash3

[86] Langmuir I The adsorption of gases on plane surfaces of glass mica and platinum J Am Chem Soc191840(9)1361ndash403

[87] Yamaguchi K-i Okamoto K Lateral supply mechanisms in selective metalorganic chemical vapordeposition Jpn J Appl Phys 199332(Part 1 No 4)1523ndash7

[88] Yamaguchi K-i Okamoto K Selective epitaxial growth of AlGaAs by atmospheric pressure ndashMOCVD using diethylgalliumchloride and diethylaluminiumchloride Jpn J Appl Phys 199029(Part 1 No 8)1408ndash14

[89] Buydens L Demeester P Van Ackere M Ackaert A Van Daele P Thickness variations duringMOVPE growth on patterned substrates J Electron Mater 199019(4)317ndash21

[90] Ando S Fukui T Facet growth of AlGaAs on GaAs with SiO2 gratings by MOCVD and applicationsto quantum well wires J Cryst Growth 198998(4)646ndash52

[91] Duchemin JP Bonnet M Koelsch F Huyghe D A new method for the growth of GaAs epilayer atlow H2 pressure J Cryst Growth 197845181ndash6

[92] Greenspan JE Blaauwa C Emmerstorfera B Glewa RW Shihb I Analysis of a time-dependentsupply mechanism in selective area growth by MOCVD J Cryst Growth 2003248405ndash10


[93] Jones AM Osowski ML Lammert RM Dantzig JA Coleman JJ Growth characterization andmodeling of ternary InGaAs-GaAs quantum-wells by selective-area metalorganic chemical-vapor-deposition J Electron Mater 199524(11)1631ndash6

[94] Alam MA People R Isaacs E Kim CY Evans-Lutterodt K Siegrist T et al Simulation and char-acterization of the selective area growth process Appl Phys Lett 199974(18)

[95] Poling BE Prausnitz JM OrsquoConnell JP The properties of gases and liquids 5th ed New YorkMcGraw Hill 2000

[96] Neufeld PD Empirical equations to calculate 16 of the transport collision integrals U(ls) J ChemPhys 197257(3)

[97] Holstein WL Thermal diffusion in metal ndash organic chemical vapor deposition J Electrochem Soc1988135(7)1788ndash93

[98] Shioda T Tomita Y Sugiyama M Shimogaki Y Nakano Y Selective area metalndashorganic vaporphase epitaxy of nitride semiconductors for multicolor emission IEEE J Sel Top Quantum Electron200915(4)1053ndash65

[99] Oh H-j Shimogaki MSN Surface reaction kinetics in metalorganic vapor phase epitaxy of GaAsthrough analyses of growth rate profile in wide-gap selective-area growth Jpn J Appl Phys 200342(Part 1 No 10)6284ndash91

[100] Dupuis N Decobert J Lagree PY Lagay N Poingt F Kazmierski C et al Mask pattern interferencein AlGaInAs selective area metal-organic vapor-phase epitaxy experimental and modeling anal-ysis J Appl Phys 2008103(11)113113ndash113113-8

[101] Shioda T Sugiyama M Shimogaki Y Nakano Y Vapor phase diffusion and surface diffusioncombined model for InGaAsP selective area metalndashorganic vapor phase epitaxy J Cryst Growth200729837ndash40

[102] Hiruma K Haga T Miyazaki M Surface migration and reaction mechanism during selectivegrowth of GaAs and AlAs by metalorganic chemical vapor deposition J Cryst Growth 1990102(4)717ndash24

[103] Ida M Shigekawa N Furuta T Ito H Kobayashi T Compositional change near the mask edge inselective InGaAs growth by low-temperature MOCVD J Cryst Growth 1996158(4)437ndash42

[104] Greenspan JE Alloy composition dependence in selective area epitaxy on InP substrates J CrystGrowth 2002236(1ndash3)273ndash80

[105] Li X Jones AM Roh SD Turnbull DA Bishop SG Coleman JJ Characteristics of GaN stripes grownby selective-area metalorganic chemical vapor deposition J Electron Mater 199726(3)306ndash10

[106] Li X Jones AM Roh SD Turnbull DA Reuter EE Gu SQ et al Correlation of surface morphologyand optical properties of GaN by conventional and selective-area MOCVD MRS Online Proc Libr1995395

[107] Leys MR Veenvliet H A study of the growth mechanism of epitaxial GaAs as grown by thetechnique of metal organic vapour phase epitaxy J Cryst Growth 198155(1)145ndash53

[108] Amano C Rudra A Grunberg P Carlin JF Ilegems M Growth temperature dependence of theinterfacet migration in chemical beam epitaxy of InP on non-planar substrates J Cryst Growth1996164(1ndash4)321ndash6

[109] Silvestre L Ougazzaden A Delprat D Ramdane A Daguet C Patriarche G Study of growth rate andcomposition variations inmetalorganic vapour phase selective area epitaxy at atmospheric pressureand application to the growth of strained layer DBR lasers J Cryst Growth 1997170(1ndash4)639ndash44

[110] Kluender JF Jones AM Lammert RM Baker JE Coleman JJ Growth characterization andmodeling of InxGa1xP stripes by selective-area MOCVD J Electron Mater 199625(9)1514ndash20

[111] Maassen M Kayser O Westphalen R Guimaraes FEG Geurts J Finders J et al Localized depo-sition of GaAsGaInP heterostructures using LP-MOVPE J Electron Mater 199221(3)257ndash64


[112] Ooi B-S McIlvaney K Street MW Helmy AS Ayling SG Bryce AC et al Selective quantum-wellintermixing in GaAs-AlGaAs structures using impurity-free vacancy diffusion IEEE J QuantumElectron 199733(10)1784ndash93

[113] Arakawa S Itoh M Kasukawa A Highly selective growth of AlGaInAs assisted by CBr4 duringMOCVD growth J Cryst Growth 2000221(1ndash4)183ndash8

[114] Tsuchiya T Shimizu J Shirai M Aoki M InGaAlAs selective-area growth on an InP substrate bymetalorganic vapor-phase epitaxy J Cryst Growth 2005276(3ndash4)439ndash45

[115] Roehle H Schroeter-Janssen H Kaiser R Large- and selective-area LP-MOVPE growth ofInGaAsP-based bulk and QW layers under nitrogen atmosphere J Cryst Growth 1997170(1ndash4)109ndash12

[116] Decobert J Dupuis N Lagree PY Lagay N Ramdane A Ougazzaden A et al Modeling andcharacterization of AlGaInAs and related materials using selective area growth by metal-organicvapor-phase epitaxy J Cryst Growth 200729828ndash31

[117] Cho AY Ballamy WC GaAs planar technology by molecular beam epitaxy (MBE) J Appl Phys 200846(2)783ndash5

[118] Okamoto A Ohata K Selective epitaxial growth of gallium arsenide by molecular beam epitaxyAppl Phys Lett 198751(19)

[119] Okamoto A Ohata K Substrate temperature lowering in GaAs selective epitaxial growth bymolecular ndash beam epitaxy J Appl Phys 198966(7)

[120] Allegretti F Inoue M Nishinaga T In-situ observation of GaAs selective epitaxy on GaAs (111)Bsubstrates J Cryst Growth 1995146(1ndash4)354ndash8

[121] Bacchin G Nishinaga T Dependence of the degree of selectivity on the Al content during theselective area growth of AlGaAs on GaAs(0 0 1) by PSEMBE J Cryst Growth 1998191(4)599ndash606

[122] Tsang WT Ilegems M Selective area growth of GaAsAlxGa1xAs multilayer structures withmolecular beam epitaxy using Si shadow masks Appl Phys Lett 197731(4)301ndash4

[123] Okamoto A Selective epitaxial growth by molecular beam epitaxy Semicond Sci Technol 19938(6)

[124] Kishino K Sekiguchi H Kikuchi A Improved Ti-mask selective-area growth (SAG) by RF-plasma-assisted molecular beam epitaxy demonstrating extremely uniform GaN nanocolumn arraysJ Cryst Growth 2009311(7)2063ndash8

[125] Yamamoto N Kondo N Nanishi Y Desorption process of Ga atoms from the mask surface inselective area growth of GaAs by electron-cyclotron-resonance plasma-excited molecular-beamepitaxy (ECR-MBE) J Cryst Growth 1991108(1ndash2)433ndash5

[126] Sugaya T Okada Y Kawabe M Selective growth of GaAs by molecular beam epitaxy Jpn J ApplPhys 199231(Part 2 No 6A)L713ndash6

[127] Nishinaga T Bacchin G Selective area MBE of GaAs AlAs and their alloys by periodic supplyepitaxy Thin Solid Films 2000367(1ndash2)6ndash12

[128] Schumann T Gotschke T Limbach F Stoica T Calarco R Selective-area catalyst-free MBE growthof GaN nanowires using a patterned oxide layer Nanotechnology 201122(9)

[129] Verma VB Elarde VC Coleman JJ An analytical model for the ordered nanopore array diode laserIEEE J Quantum Electron 200945(1ndash2)10ndash20

[130] Elarde VC Coleman JJ Nanoscale selective area epitaxy for optoelectronic devices Prog QuantumElectron 200731(6)225ndash57

[131] Claps R Dimitropoulos D Raghunathan V Han Y Jalali B Observation of stimulated Ramanamplification in silicon waveguides Opt Express 200311(15)1731ndash9

[132] Boyraz O Jalali B Demonstration of a silicon Raman laser Opt Express 200412(21)5269ndash73


[133] Dadap JI Espinola RL Osgood RM McNab SJ Vlasov YA et al Spontaneous Raman scattering inultrasmall silicon waveguides Opt Lett 200429(23)2755ndash7

[134] Espinola RL Dadap JI Osgood Jr RM McNab SJ Vlasov YA Raman amplification in ultrasmallsilicon-on-insulator wire waveguides Opt Express 200412(16)3713ndash8

[135] Almeida VR Barrios CA Panepucci RR Lipson M Foster MA Ouzounov DG et al All-opticalswitching on a silicon chip Opt Lett 200429(24)2867ndash9

[136] Rong HS Jones R Liu A Cohen O Hak D Fang A et al A continuous-wave Raman silicon laserNature 2005433(7027)725ndash8

[137] Rong HS Liu A Jones R Cohen O Hak D Nicolaescu R et al An all-silicon Raman laser Nature2005433(7023)292ndash4

[138] Jalali B Fathpour S Silicon photonics J Lightwave Technol 200624(12)4600ndash15

[139] Xia FN Rooks M Sekaric L Vlasov Y Ultra-compact high order ring resonator filters using sub-micron silicon photonic wires for on-chip optical interconnects Opt Express 200715(19)11934ndash41

[140] Rong HS Xu S Cohen O Raday O Lee M Sih V et al A cascaded silicon Raman laser NatPhotonics 20082(3)170ndash4

[141] Jalali B Silicon photonics nonlinear optics in the mid-infrared Nat Photonics 20104(8)506ndash8

[142] Wen H Wen YH Kuzucu O Hou T Lipson M Gaeta AL All-optical switching of a single resonancein silicon ring resonators Opt Lett 201136(8)1413ndash5

[143] Martensson T Svensson CPT Wacaser BA Larsson MW Seifert W Deppert K et al Epitaxial III-Vnanowires on silicon Nano Lett 20044(10)1987ndash90

[144] Tomioka K Tanaka T Hara S Hiruma K Fukui T IIIndashV nanowires on Si substrate selective-areagrowth and device applications IEEE J Sel Top Quantum Electron 201117(4)1112ndash29

[145] Noborisaka J Motohisa J Hara S Fukui T Fabrication and characterization of freestanding GaAsAlGaAs core-shell nanowires and AlGaAs nanotubes by using selective-area metalorganic vaporphase epitaxy Appl Phys Lett 200587(9)

[146] Ikejiri K Noborisaka J Hara S Motohisa J Fukui T Mechanism of catalyst-free growth of GaAsnanowires by selective area MOVPE J Cryst Growth 2007298616ndash9

[147] Tomioka K Motohisa J Hara S Fukui T Control of InAs nanowire growth directions on Si NanoLett 20088(10)3475ndash80

[148] Katsuhiro T Kobayashi Y Motohisa J Hara S Fukui T Selective-area growth of vertically alignedGaAs and GaAsAlGaAs corendashshell nanowires on Si(111) substrate Nanotechnology 200920(14)145302

[149] Tomioka K Motohisa J Hara S Hiruma K Fukui T GaAsAlGaAs core multishell nanowire-basedlight-emitting diodes on Si Nano Lett 201010(5)1639ndash44

10 Selective Area Masked Growth (Nano to Micro)

101 Introduction

102 Methodology of SAG

1021 Growth Dynamics

10211 Growth Modes

10212 MetalndashOrganic Chemical Vapor Deposition

10213 Vapor-Phase Diffusion and Surface Diffusion in SAG


1023 SAG with MOCVD

1024 SAG in MBE

103 Applications of Selective Area Masked Growth

1031 Monolithically Integrated Dual-Wavelength Source Electroabsorption Modulators and Y-Junction Coupler



104 Summary

Acknowledgments

References


confined structures and devices are of great importance by themselves a more exciting

future for optoelectronic devices and systems requires planar integration of individual

devices to achieve compactness lower loss higher robustness and more superior per-

formance Selective area growth (SAG) or alternatively selective area epitaxy (SAE)

combines the benefits of both epitaxial growth and lithography techniques to enable

three-dimensionally defined and controlled growth of semiconductor materials

Lithography can be used to define device features in the plane perpendicular to the

direction of selectively grown crystal in the nanometer regime which allows the inte-

gration of a large number of devices monolithically on a single substrate It provides a

promising solution to the challenge of creating sophisticated integrated optoelectronic

and photonic systems

There are two basic types of SAG [12] The first type of SAG uses a dielectric insu-

lating mask to inhibit the deposition of materials wherever the mask is present [3]

Ideally epitaxial single crystal will grow uniformly only in the windows opened in the

mask In practice polycrystalline deposition may occur on the insulating mask

Polycrystalline growth on the mask can be avoided by choosing a halogen-based pre-

cursor and suitable growth conditions [24ndash6] Because the epitaxial growth process is

mass conserved no deposition on the mask leads to enhanced growth rate on the

unmasked area especially close to the boundary of the mask As a result if the di-

mensions of the window are large compared with the effective diffusion length of the

constituents the crystal layer deposited in the window may exhibit substantial lateral

variation in thickness and composition To predict the growth enhancement effect and

to control the thickness and composition of the deposited layers much effort has been

devoted to develop models accurately that describe the growth kinetics [7ndash19] High

lateral uniformity can be achieved for certain carefully designed structures and devices

[320] The second type of SAG involves depositing materials on a patterned substrate

without a mask Etching and lithography are used to define patterns on the substrate

before the deposition Localized epitaxial growth takes place in the patterned features

This technique has attracted a lot of attention because it may take only a single growth

step to form the desired structure But it is rather more difficult to model the preferential

growth of different species on different crystallographic planes In this chapter we focus

on the first type of SAG We start by reviewing briefly the history of the development of

SAG and discuss the current frontiers of this technology In the next section we intro-

duce the theoretical model that describes the selective growth kinetics in MOCVD

accurately We chose MOCVD as the exemplary technique because of its versatility in

fabricating semiconductor compounds and alloys We cover briefly the selective growth

model in MBE in Section 102 Section 103 includes provides a few examples that

illustrate how to use SAG to achieve optoelectronic integration

The idea of using photolithographic techniques to assist with the fabrication and

packaging of semiconductor devices dates back to the late 1950s [2122] During the

1960s selective epitaxial deposition of silicon and gallium arsenide was achieved in

different industrial research laboratories [23ndash25] In those early reports the focus was on











































































































(a)

(b)




[74] is defined as

f frac14 Da0

a0

(101)



layer







hc frac14 a0

2ffiffiffi2

ppf


ln

hc

ffiffiffi2

p

a0

thorn 1

(102)



(103)






























MBE in Section 1024






(a)

(b)

Baffle

SusceptorRF coil

RF coil

Susceptor





equation





















760mbar (107)




Precursor a b (K)


d







in Section 1023






(a)(b) (c)


Substrate

X

z




























used [24588]




























of SAG




















3D is

v2n

vx2thorn v2n

vy2thorn v2n

vz2frac14 0 (108)








n = n0


dndx = 0

dndx = 0

dndz = 0 dn

dz = 0

dn kndz D=

W


Substrate

c

x0

z

Bou

ndar

y la

yer

d





vn

vx

xfrac140C

frac14 0 (1010)




vn

vz

zfrac140

frac14 0 (1011)




Dvn

vz

zfrac140

frac14 kn (1012)









DAB frac14 3

16

4pkBTMAB

1=2

nps2ABUD

fD (1013)






MAB frac14 2MAMB

MA thornMB

(1014)




from 10 to 11



DAB frac14 000266T 3=2

PM1=2AB s2

ABUD

(1015)



j frac14 4ε

sr

12sr

6(1016)


sAB frac14 1




Eqn (1018) [96]

UD frac14 106036






T frac14 kbT

εAB

(1019)






k frac14 1

4

h

1 h=2


pM

rfrac14 k0e

eth EakBT

THORN (1020)

























1

2

3

1

3

2

4

1

2R

OIMcalculation

OIMcalculation

OIMcalculation

A1InAs

GaA1As

A1GaInAs(a)

(b)


100 200 300

(c)R

R

4

3









in Eqn (1021)




(1021)

300

250

200

150

100

50

500 600 700 1000 1100 1200 13000

Dk

(μm

)

T (ordmC)




600 650 700 750

T (ordmC)

800 850 900


300

250

200

150

Dk

(μm

)

100

50

0





GRE frac14 n

nsp

frac14 n

n0

1thorn d

D=k

(1022)



nsp frac14 n0

1thorn d

D=k

1

(1023)








geometry

1023 SAG with MOCVD






































400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References











































































































(a)

(b)




[74] is defined as

f frac14 Da0

a0

(101)



layer







hc frac14 a0

2ffiffiffi2

ppf


ln

hc

ffiffiffi2

p

a0

thorn 1

(102)



(103)






























MBE in Section 1024






(a)

(b)

Baffle

SusceptorRF coil

RF coil

Susceptor





equation





















760mbar (107)




Precursor a b (K)


d







in Section 1023






(a)(b) (c)


Substrate

X

z




























used [24588]




























of SAG




















3D is

v2n

vx2thorn v2n

vy2thorn v2n

vz2frac14 0 (108)








n = n0


dndx = 0

dndx = 0

dndz = 0 dn

dz = 0

dn kndz D=

W


Substrate

c

x0

z

Bou

ndar

y la

yer

d





vn

vx

xfrac140C

frac14 0 (1010)




vn

vz

zfrac140

frac14 0 (1011)




Dvn

vz

zfrac140

frac14 kn (1012)









DAB frac14 3

16

4pkBTMAB

1=2

nps2ABUD

fD (1013)






MAB frac14 2MAMB

MA thornMB

(1014)




from 10 to 11



DAB frac14 000266T 3=2

PM1=2AB s2

ABUD

(1015)



j frac14 4ε

sr

12sr

6(1016)


sAB frac14 1




Eqn (1018) [96]

UD frac14 106036






T frac14 kbT

εAB

(1019)






k frac14 1

4

h

1 h=2


pM

rfrac14 k0e

eth EakBT

THORN (1020)

























1

2

3

1

3

2

4

1

2R

OIMcalculation

OIMcalculation

OIMcalculation

A1InAs

GaA1As

A1GaInAs(a)

(b)


100 200 300

(c)R

R

4

3









in Eqn (1021)




(1021)

300

250

200

150

100

50

500 600 700 1000 1100 1200 13000

Dk

(μm

)

T (ordmC)




600 650 700 750

T (ordmC)

800 850 900


300

250

200

150

Dk

(μm

)

100

50

0





GRE frac14 n

nsp

frac14 n

n0

1thorn d

D=k

(1022)



nsp frac14 n0

1thorn d

D=k

1

(1023)








geometry

1023 SAG with MOCVD






































400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References



[74] is defined as

f frac14 Da0

a0

(101)



layer







hc frac14 a0

2ffiffiffi2

ppf


ln

hc

ffiffiffi2

p

a0

thorn 1

(102)



(103)






























MBE in Section 1024






(a)

(b)

Baffle

SusceptorRF coil

RF coil

Susceptor





equation





















760mbar (107)




Precursor a b (K)


d







in Section 1023






(a)(b) (c)


Substrate

X

z




























used [24588]




























of SAG




















3D is

v2n

vx2thorn v2n

vy2thorn v2n

vz2frac14 0 (108)








n = n0


dndx = 0

dndx = 0

dndz = 0 dn

dz = 0

dn kndz D=

W


Substrate

c

x0

z

Bou

ndar

y la

yer

d





vn

vx

xfrac140C

frac14 0 (1010)




vn

vz

zfrac140

frac14 0 (1011)




Dvn

vz

zfrac140

frac14 kn (1012)









DAB frac14 3

16

4pkBTMAB

1=2

nps2ABUD

fD (1013)






MAB frac14 2MAMB

MA thornMB

(1014)




from 10 to 11



DAB frac14 000266T 3=2

PM1=2AB s2

ABUD

(1015)



j frac14 4ε

sr

12sr

6(1016)


sAB frac14 1




Eqn (1018) [96]

UD frac14 106036






T frac14 kbT

εAB

(1019)






k frac14 1

4

h

1 h=2


pM

rfrac14 k0e

eth EakBT

THORN (1020)

























1

2

3

1

3

2

4

1

2R

OIMcalculation

OIMcalculation

OIMcalculation

A1InAs

GaA1As

A1GaInAs(a)

(b)


100 200 300

(c)R

R

4

3









in Eqn (1021)




(1021)

300

250

200

150

100

50

500 600 700 1000 1100 1200 13000

Dk

(μm

)

T (ordmC)




600 650 700 750

T (ordmC)

800 850 900


300

250

200

150

Dk

(μm

)

100

50

0





GRE frac14 n

nsp

frac14 n

n0

1thorn d

D=k

(1022)



nsp frac14 n0

1thorn d

D=k

1

(1023)








geometry

1023 SAG with MOCVD






































400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References








MBE in Section 1024






(a)

(b)

Baffle

SusceptorRF coil

RF coil

Susceptor





equation





















760mbar (107)




Precursor a b (K)


d







in Section 1023






(a)(b) (c)


Substrate

X

z




























used [24588]




























of SAG




















3D is

v2n

vx2thorn v2n

vy2thorn v2n

vz2frac14 0 (108)








n = n0


dndx = 0

dndx = 0

dndz = 0 dn

dz = 0

dn kndz D=

W


Substrate

c

x0

z

Bou

ndar

y la

yer

d





vn

vx

xfrac140C

frac14 0 (1010)




vn

vz

zfrac140

frac14 0 (1011)




Dvn

vz

zfrac140

frac14 kn (1012)









DAB frac14 3

16

4pkBTMAB

1=2

nps2ABUD

fD (1013)






MAB frac14 2MAMB

MA thornMB

(1014)




from 10 to 11



DAB frac14 000266T 3=2

PM1=2AB s2

ABUD

(1015)



j frac14 4ε

sr

12sr

6(1016)


sAB frac14 1




Eqn (1018) [96]

UD frac14 106036






T frac14 kbT

εAB

(1019)






k frac14 1

4

h

1 h=2


pM

rfrac14 k0e

eth EakBT

THORN (1020)

























1

2

3

1

3

2

4

1

2R

OIMcalculation

OIMcalculation

OIMcalculation

A1InAs

GaA1As

A1GaInAs(a)

(b)


100 200 300

(c)R

R

4

3









in Eqn (1021)




(1021)

300

250

200

150

100

50

500 600 700 1000 1100 1200 13000

Dk

(μm

)

T (ordmC)




600 650 700 750

T (ordmC)

800 850 900


300

250

200

150

Dk

(μm

)

100

50

0





GRE frac14 n

nsp

frac14 n

n0

1thorn d

D=k

(1022)



nsp frac14 n0

1thorn d

D=k

1

(1023)








geometry

1023 SAG with MOCVD






































400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References




equation





















760mbar (107)




Precursor a b (K)


d







in Section 1023






(a)(b) (c)


Substrate

X

z




























used [24588]




























of SAG




















3D is

v2n

vx2thorn v2n

vy2thorn v2n

vz2frac14 0 (108)








n = n0


dndx = 0

dndx = 0

dndz = 0 dn

dz = 0

dn kndz D=

W


Substrate

c

x0

z

Bou

ndar

y la

yer

d





vn

vx

xfrac140C

frac14 0 (1010)




vn

vz

zfrac140

frac14 0 (1011)




Dvn

vz

zfrac140

frac14 kn (1012)









DAB frac14 3

16

4pkBTMAB

1=2

nps2ABUD

fD (1013)






MAB frac14 2MAMB

MA thornMB

(1014)




from 10 to 11



DAB frac14 000266T 3=2

PM1=2AB s2

ABUD

(1015)



j frac14 4ε

sr

12sr

6(1016)


sAB frac14 1




Eqn (1018) [96]

UD frac14 106036






T frac14 kbT

εAB

(1019)






k frac14 1

4

h

1 h=2


pM

rfrac14 k0e

eth EakBT

THORN (1020)

























1

2

3

1

3

2

4

1

2R

OIMcalculation

OIMcalculation

OIMcalculation

A1InAs

GaA1As

A1GaInAs(a)

(b)


100 200 300

(c)R

R

4

3









in Eqn (1021)




(1021)

300

250

200

150

100

50

500 600 700 1000 1100 1200 13000

Dk

(μm

)

T (ordmC)




600 650 700 750

T (ordmC)

800 850 900


300

250

200

150

Dk

(μm

)

100

50

0





GRE frac14 n

nsp

frac14 n

n0

1thorn d

D=k

(1022)



nsp frac14 n0

1thorn d

D=k

1

(1023)








geometry

1023 SAG with MOCVD






































400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References

d







in Section 1023






(a)(b) (c)


Substrate

X

z




























used [24588]




























of SAG




















3D is

v2n

vx2thorn v2n

vy2thorn v2n

vz2frac14 0 (108)








n = n0


dndx = 0

dndx = 0

dndz = 0 dn

dz = 0

dn kndz D=

W


Substrate

c

x0

z

Bou

ndar

y la

yer

d





vn

vx

xfrac140C

frac14 0 (1010)




vn

vz

zfrac140

frac14 0 (1011)




Dvn

vz

zfrac140

frac14 kn (1012)









DAB frac14 3

16

4pkBTMAB

1=2

nps2ABUD

fD (1013)






MAB frac14 2MAMB

MA thornMB

(1014)




from 10 to 11



DAB frac14 000266T 3=2

PM1=2AB s2

ABUD

(1015)



j frac14 4ε

sr

12sr

6(1016)


sAB frac14 1




Eqn (1018) [96]

UD frac14 106036






T frac14 kbT

εAB

(1019)






k frac14 1

4

h

1 h=2


pM

rfrac14 k0e

eth EakBT

THORN (1020)

























1

2

3

1

3

2

4

1

2R

OIMcalculation

OIMcalculation

OIMcalculation

A1InAs

GaA1As

A1GaInAs(a)

(b)


100 200 300

(c)R

R

4

3









in Eqn (1021)




(1021)

300

250

200

150

100

50

500 600 700 1000 1100 1200 13000

Dk

(μm

)

T (ordmC)




600 650 700 750

T (ordmC)

800 850 900


300

250

200

150

Dk

(μm

)

100

50

0





GRE frac14 n

nsp

frac14 n

n0

1thorn d

D=k

(1022)



nsp frac14 n0

1thorn d

D=k

1

(1023)








geometry

1023 SAG with MOCVD






































400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References



























used [24588]




























of SAG




















3D is

v2n

vx2thorn v2n

vy2thorn v2n

vz2frac14 0 (108)








n = n0


dndx = 0

dndx = 0

dndz = 0 dn

dz = 0

dn kndz D=

W


Substrate

c

x0

z

Bou

ndar

y la

yer

d





vn

vx

xfrac140C

frac14 0 (1010)




vn

vz

zfrac140

frac14 0 (1011)




Dvn

vz

zfrac140

frac14 kn (1012)









DAB frac14 3

16

4pkBTMAB

1=2

nps2ABUD

fD (1013)






MAB frac14 2MAMB

MA thornMB

(1014)




from 10 to 11



DAB frac14 000266T 3=2

PM1=2AB s2

ABUD

(1015)



j frac14 4ε

sr

12sr

6(1016)


sAB frac14 1




Eqn (1018) [96]

UD frac14 106036






T frac14 kbT

εAB

(1019)






k frac14 1

4

h

1 h=2


pM

rfrac14 k0e

eth EakBT

THORN (1020)

























1

2

3

1

3

2

4

1

2R

OIMcalculation

OIMcalculation

OIMcalculation

A1InAs

GaA1As

A1GaInAs(a)

(b)


100 200 300

(c)R

R

4

3









in Eqn (1021)




(1021)

300

250

200

150

100

50

500 600 700 1000 1100 1200 13000

Dk

(μm

)

T (ordmC)




600 650 700 750

T (ordmC)

800 850 900


300

250

200

150

Dk

(μm

)

100

50

0





GRE frac14 n

nsp

frac14 n

n0

1thorn d

D=k

(1022)



nsp frac14 n0

1thorn d

D=k

1

(1023)








geometry

1023 SAG with MOCVD






































400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References














of SAG




















3D is

v2n

vx2thorn v2n

vy2thorn v2n

vz2frac14 0 (108)








n = n0


dndx = 0

dndx = 0

dndz = 0 dn

dz = 0

dn kndz D=

W


Substrate

c

x0

z

Bou

ndar

y la

yer

d





vn

vx

xfrac140C

frac14 0 (1010)




vn

vz

zfrac140

frac14 0 (1011)




Dvn

vz

zfrac140

frac14 kn (1012)









DAB frac14 3

16

4pkBTMAB

1=2

nps2ABUD

fD (1013)






MAB frac14 2MAMB

MA thornMB

(1014)




from 10 to 11



DAB frac14 000266T 3=2

PM1=2AB s2

ABUD

(1015)



j frac14 4ε

sr

12sr

6(1016)


sAB frac14 1




Eqn (1018) [96]

UD frac14 106036






T frac14 kbT

εAB

(1019)






k frac14 1

4

h

1 h=2


pM

rfrac14 k0e

eth EakBT

THORN (1020)

























1

2

3

1

3

2

4

1

2R

OIMcalculation

OIMcalculation

OIMcalculation

A1InAs

GaA1As

A1GaInAs(a)

(b)


100 200 300

(c)R

R

4

3









in Eqn (1021)




(1021)

300

250

200

150

100

50

500 600 700 1000 1100 1200 13000

Dk

(μm

)

T (ordmC)




600 650 700 750

T (ordmC)

800 850 900


300

250

200

150

Dk

(μm

)

100

50

0





GRE frac14 n

nsp

frac14 n

n0

1thorn d

D=k

(1022)



nsp frac14 n0

1thorn d

D=k

1

(1023)








geometry

1023 SAG with MOCVD






































400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References


n = n0


dndx = 0

dndx = 0

dndz = 0 dn

dz = 0

dn kndz D=

W


Substrate

c

x0

z

Bou

ndar

y la

yer

d





vn

vx

xfrac140C

frac14 0 (1010)




vn

vz

zfrac140

frac14 0 (1011)




Dvn

vz

zfrac140

frac14 kn (1012)









DAB frac14 3

16

4pkBTMAB

1=2

nps2ABUD

fD (1013)






MAB frac14 2MAMB

MA thornMB

(1014)




from 10 to 11



DAB frac14 000266T 3=2

PM1=2AB s2

ABUD

(1015)



j frac14 4ε

sr

12sr

6(1016)


sAB frac14 1




Eqn (1018) [96]

UD frac14 106036






T frac14 kbT

εAB

(1019)






k frac14 1

4

h

1 h=2


pM

rfrac14 k0e

eth EakBT

THORN (1020)

























1

2

3

1

3

2

4

1

2R

OIMcalculation

OIMcalculation

OIMcalculation

A1InAs

GaA1As

A1GaInAs(a)

(b)


100 200 300

(c)R

R

4

3









in Eqn (1021)




(1021)

300

250

200

150

100

50

500 600 700 1000 1100 1200 13000

Dk

(μm

)

T (ordmC)




600 650 700 750

T (ordmC)

800 850 900


300

250

200

150

Dk

(μm

)

100

50

0





GRE frac14 n

nsp

frac14 n

n0

1thorn d

D=k

(1022)



nsp frac14 n0

1thorn d

D=k

1

(1023)








geometry

1023 SAG with MOCVD






































400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References





DAB frac14 3

16

4pkBTMAB

1=2

nps2ABUD

fD (1013)






MAB frac14 2MAMB

MA thornMB

(1014)




from 10 to 11



DAB frac14 000266T 3=2

PM1=2AB s2

ABUD

(1015)



j frac14 4ε

sr

12sr

6(1016)


sAB frac14 1




Eqn (1018) [96]

UD frac14 106036






T frac14 kbT

εAB

(1019)






k frac14 1

4

h

1 h=2


pM

rfrac14 k0e

eth EakBT

THORN (1020)

























1

2

3

1

3

2

4

1

2R

OIMcalculation

OIMcalculation

OIMcalculation

A1InAs

GaA1As

A1GaInAs(a)

(b)


100 200 300

(c)R

R

4

3









in Eqn (1021)




(1021)

300

250

200

150

100

50

500 600 700 1000 1100 1200 13000

Dk

(μm

)

T (ordmC)




600 650 700 750

T (ordmC)

800 850 900


300

250

200

150

Dk

(μm

)

100

50

0





GRE frac14 n

nsp

frac14 n

n0

1thorn d

D=k

(1022)



nsp frac14 n0

1thorn d

D=k

1

(1023)








geometry

1023 SAG with MOCVD






































400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References






k frac14 1

4

h

1 h=2


pM

rfrac14 k0e

eth EakBT

THORN (1020)

























1

2

3

1

3

2

4

1

2R

OIMcalculation

OIMcalculation

OIMcalculation

A1InAs

GaA1As

A1GaInAs(a)

(b)


100 200 300

(c)R

R

4

3









in Eqn (1021)




(1021)

300

250

200

150

100

50

500 600 700 1000 1100 1200 13000

Dk

(μm

)

T (ordmC)




600 650 700 750

T (ordmC)

800 850 900


300

250

200

150

Dk

(μm

)

100

50

0





GRE frac14 n

nsp

frac14 n

n0

1thorn d

D=k

(1022)



nsp frac14 n0

1thorn d

D=k

1

(1023)








geometry

1023 SAG with MOCVD






































400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References

1

2

3

1

3

2

4

1

2R

OIMcalculation

OIMcalculation

OIMcalculation

A1InAs

GaA1As

A1GaInAs(a)

(b)


100 200 300

(c)R

R

4

3









in Eqn (1021)




(1021)

300

250

200

150

100

50

500 600 700 1000 1100 1200 13000

Dk

(μm

)

T (ordmC)




600 650 700 750

T (ordmC)

800 850 900


300

250

200

150

Dk

(μm

)

100

50

0





GRE frac14 n

nsp

frac14 n

n0

1thorn d

D=k

(1022)



nsp frac14 n0

1thorn d

D=k

1

(1023)








geometry

1023 SAG with MOCVD






































400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References

600 650 700 750

T (ordmC)

800 850 900


300

250

200

150

Dk

(μm

)

100

50

0





GRE frac14 n

nsp

frac14 n

n0

1thorn d

D=k

(1022)



nsp frac14 n0

1thorn d

D=k

1

(1023)








geometry

1023 SAG with MOCVD






































400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References

































400 170 mm 59 mm550 100 mm 63 mm630 40 mm 96 mm

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References

Mask

(a)

(b)

Substrate

Mask

Mask Mask

Substrate





















compounds





1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References

1234

1

2

3

1

2R

A1As OIMVPD fitting

GaAs

(a)

(b)

InP


100 200 300

(c)R

R

3

OIMVPD fitting

OIMVPD fitting


























28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References

28

26

24

22

2

18

16

10 10 20 30 40


12

14Gro

wth

rate

enh

ance

men

t


40 μm

60 μm





























24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References

24

22

2

18

16

10 10 20 30 40

Mask width (microm)

50 60 70 80

12

14

Gro

wth

rate

enh

ance

men

t


20 microm

40 microm

60 microm

047

048

046

045

044

043

040 20 40

Mask width (microm)

60 80 100 120

041

042

Ga

com

posi

tion


20 microm

40 microm

(a)

(b)



1024 SAG in MBE

























dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References













dtfrac14 D

d2n

dx2thorn R n

s(1024)



































































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References






































Channels1 and 2



GaAsnsubstrate
































Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References


Modulatorsection

Modulatorsection



Channel 1

Channel 2











































5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References
























5

4

3

2

1

00 10 20 30 40 50 60 70 80 90

Current (mA)

Channel 1Channel 2

Pow

er (m

W)

099

V2 = ndash2

V1 = ndash2

V1 = 0

V2 = 0

V2 = 0 V1 = 0
































GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References






























GaAs Barrier

GaAsBarrier





























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References



























Inte

nsity

(arb

uni

ts)

950 955 960 965 970Wavelength (nm)

Quantumwell

IQDA


8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References

8E+207E+20

6E+205E+20

4E+203E+20

2E+201E+20

01288 1290 1292 1294 1296 950 955 960 965 970

Energy (meV)

Inte

nsity

(arb

uni

ts)

Den

sity

of s

tate

scm

3 eV

(a) (b)

Wavelength (nm)



































fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References




fully
































































(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References



























(a) (b)

1 1prime

p-GaAs

p-AlGaAs

p-GaAs

n-AlGaAs

n-GaAs

SiO2n-Si(111)

EL

inte

nsity

(arb

uni

ts)

RT


400 mA

184 mA (x15)

130 mA (x30)

065 mA (x20)

050 mA (x30)

PL at RT










































































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References

















































integration circuit

































































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References
















































































































































101 Introduction



10211 Growth Modes




1023 SAG with MOCVD

1024 SAG in MBE





104 Summary

Acknowledgments

References

handbook of crystal growth || selective area masked growth (nano to micro)

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