application of plasmons and fabrication methods enzo di...
TRANSCRIPT
![Page 1: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/1.jpg)
Department of Experimental Medicine
Università della“Magna Græcia” di Catanzaro, Italy
BIONEM Laboratory http:\\bionem.unicz.it
&
Nanobioscience lab at IIT (Italian Institute of Technology)
http:\\www.iit.it
Contact: [email protected]
Application of Plasmons and fabrication methods
Enzo Di Fabrizio
Varenna 12 July 2010
![Page 2: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/2.jpg)
Enzo Di Fabrizio group leader (BIONEM)
F. De Angelis, G. Das, C. Liberale,
R. Proietti, P. Candeloro, F. Gentile F. Mecarini,
M. L. Coluccio BIONEM group (Bio&Nano engineering for Medicine)
Department of Experimental Medicine,
University of Magna Græcia di Catanzaro, Italy
Acknowledgements
M. Lazzarino -TASC-Trieste, Alpan Beck- CBMM. Patrini, M. Galli, L.C. Andreani
Department of Physics “A. Volta”, University of Pavia, Italy
Contributors
![Page 3: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/3.jpg)
Campus
“Salvatore Venuta”
University of Magna Graecia location
IIT-Genoa
Nanobioscience lab at IIT (Italian Institute
of Technology)
http:\\www.iit.it
![Page 4: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/4.jpg)
Outline
• Combination of AFM & Raman Spectroscopy
• SENSe (Suface enhanced Nano SEnsor)
• Adiabatic nanocones on AFM cantilevers
• Self similar nanospheres for SERS
• Superhydrophobic devices
• Integration of Sup-hydro-dev and Plasmonics
![Page 5: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/5.jpg)
Challenge 1:
combination of AFM-Raman spectroscopy
Main advantages of Raman
1. “Water-transparent”
2. Low damaging
3. Analysis vs temperature
4. Small samples (da 5 a 30 μl)
5. Fast measurements
Medical&biological applications
1. Molecular structure
2. Secondary structure observation
3. Amino-acidic composition
4. Protein-Protein interactions
Main disadvantage:
Low scattering cross-section
Structured surface
![Page 6: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/6.jpg)
Challenge 1:
combination of AFM-Raman spectroscopy
Open challenge:
nanodevice on a cantilever efficiently
acting as AFM tip and as a nanontenna
for Raman scattering.
![Page 7: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/7.jpg)
Plasmons
![Page 8: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/8.jpg)
Scatt. eff. small sfere
Scattering efficiency from a small sfere of nobel metal
![Page 9: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/9.jpg)
Enhanced Local Fields
in Proximity of Metal
Nanoparticle are
Nanoscale-Localized
Nanoplasmonics: ~10 nm
Field Enhancement or
Quality Factor:
10010~Im
Re
m
mQ
Nanoplasmonics in a nutshell
Lattice Electrons
Localized Surface Plasmon:
Skin depth, ~25 nm
Spatial dispersion/Nonlocality radius, ~2 nmFv
Mean free path, ~40 nm
Reduced wavelength, ~100 nm
Polarizability:
dm
dmR2
3
dm 2
Courtesy by M. Stockman
![Page 10: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/10.jpg)
Padova 13-12-07
![Page 11: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/11.jpg)
Padova 13-12-07
![Page 12: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/12.jpg)
![Page 13: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/13.jpg)
Surface plasmon polariton (SPP) in a planar layered medium is a TM wave where
in an i-th medium layer at a point (y, z) for a wave propagating in the y direction
Boundary conditions are continuity across the interface plane of
z
H
k
iEH x
yx
0
and
ckkk
zyiHk
zyiE
ikyzBzAk
zyiE
ikyzBzAzyiH
y
x
i
z
iiii
i
iy
iiiix
0
0
;
);,,(),,(
),exp()exp()exp(),,(
),exp()exp()exp(),,(
x
y
z
Courtesy by M. Stockman
![Page 14: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/14.jpg)
Metal-Dielectric Interface
For a two-medium system, the SPP wave vector is found as a function of frequency
(dispersion relation):
Evanescent decay exponents in these two media are found as
21
21
ck
21
2
11
c21
2
22
c
From these, it follows that for the existence of SPPs, it is necessary and sufficient that
0 and 0 2121
Courtesy by M. Stockman
![Page 15: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/15.jpg)
Dielectric permittivity for silver and gold in optical region
P. B. Johnson and R. W. Christy, "Optical-Constants of Noble-Metals," Physical
Review B 6, 4370-4379 (1972).
Courtesy by M. Stockman
![Page 16: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/16.jpg)
![Page 17: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/17.jpg)
SERS and nanoparticles
Local field depends mainly on:
1) The size and shape of metal
nanoparticles (about /10)
1) The distance between metal
nanoparticles (about /100)(Both difficult to control with colloidal
nanoparticle)
![Page 18: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/18.jpg)
2
Concentration of optical (electromagnetic wave)
energy in free space: we cannot do better than /2
…
courtesy of M. Stockman
![Page 19: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/19.jpg)
Problems in Nanooptics
Microscale
Delivery of energy
to nanoscale:
Adiabatically
converting
propagating EM
wave to local fields
Enhancement and
control of the local
nanoscale fields.
Enhanced near-
field responses
Generation of
local fields on
nanoscale
Far field
collection
(if possible)
courtesy of M. Stockman
![Page 20: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/20.jpg)
![Page 21: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/21.jpg)
![Page 22: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/22.jpg)
![Page 23: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/23.jpg)
![Page 24: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/24.jpg)
![Page 25: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/25.jpg)
![Page 26: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/26.jpg)
Nanofabrication
Nanofabrication can generally be divided into two categories based on the approach:
“Top-Down”: Fabrication of device structures via monolithic processing on the nanoscale.
“Bottom-Up”: Fabrication of device structures via systematic assembly of
atoms, molecules or other basic units of matter.
![Page 27: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/27.jpg)
Nanotech and Microfabrication• Microfabrication is a top-down technique utilizing the
following processes in sequential fashion:
– Film Deposition
• CVD, PVD
– Photolithography
• Optical exposure, PR
– Etching
• Aqueous, plasma
Many of these techniques are useful, directly or indirectly in
nanofabrication
![Page 28: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/28.jpg)
![Page 29: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/29.jpg)
![Page 30: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/30.jpg)
L 'autoassemblaggio si verifica spontaneamente
quando molecole dotate di un apposito «gruppo
terminale»
(in giollo} si ancorano alIa superficie di un
substrato
Dip-pen litho: top down-bottom up Hybrid technique
![Page 31: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/31.jpg)
Electrons to “write” small
![Page 32: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/32.jpg)
The “miniaturized” Bible
Overall view of the sampleDetailed view. One line has 100nm
One of the typical defects encountered
Courtesy by R. Malureanu
![Page 33: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/33.jpg)
Sample
CrossBeam® Operation
SE
M
Scan Generator SEM
Scan Generator
FIB
Monitor
Sync
SED
Both beams are scanned
completely independent from
each other and the SED
Signal is synchronised to the
SEM scan. This results in the
CrossBeam™ operation
feature:
The ion milling process
can be imaged using the
SEM in realtime!
Sync
Pattern
Generator
The Cross-Beam equipped by a good lithography pattern generator
tool became an excellent instrument for the micro and nano
fabrication
![Page 34: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/34.jpg)
Gas Injection System
5 reservoirs for up to 5 different gases
5 separate injection lines (one per gas)
All reservoirs and injection lines can be heated separately
Fully software controlled
Pneumatic actuators
Crossbeam chamber flange3 axis micropositioner
Injection lines
NozzlesVacuum jar with
precursor capsules inside
![Page 35: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/35.jpg)
1. Adsorption of the gas molecules on
to the substrate surface
2. Activation of an chemical reaction
of the gas molecules with the
substrate by the Ion- / E-beam
3. Generation of volatile reaction-
products :
GaCl3 SiCl4 SiF4
4. Evaporation of volatile species and
sputtering of non volatile species
Focused Ion Beam milling and gas assisted etch
Gas assisted etch
Available on LEO CrossBeas:
XeF2,
![Page 36: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/36.jpg)
1. Adsorption of the precursor
molecules on the substrate
2. Ion beam / e-beam induced
dissociation of the gas
molecules
3. Deposition of the material
atoms and removal of the
organic ligands
Beam induced deposition
Available on LEO CrossBeams:
Metals: W, Pt
Insulator: SiO2
Tungsten wall
Tungsten deposition
![Page 37: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/37.jpg)
How to make things small
![Page 38: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/38.jpg)
Ions to sculpture
![Page 39: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/39.jpg)
Focused Ion Beam - Applications
Diamond particle on
sapphire stalk
![Page 40: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/40.jpg)
Focused Ion Beam - Applications
Microsculpture by FIB
![Page 41: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/41.jpg)
Catanzaro 31-05-07
a-Si 2D Photonic Crys.
Coll. F. Pirri group
3D PH. Crys. By X-ray litho 2D Bragg reflector Si/SiO2 Coll. F. Priolo
2D-3D structures
INFM network LIF@TASC
Topographic lenses
![Page 42: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/42.jpg)
Effects produced by electron bombardment of a
material.
Two major factors control which effects can be detected
from the interaction
volume. First, some effects are not produced from certain
parts of the interaction volume (Figure 2.1b).
Beam electrons lose energy as they traverse the sample
due to interactions with it and if too much energy is
required to produce an effect, it will not be possible to
produce it from deeper portions of the volume. Second,
the degree to which an effect, once produced, can be
observed is controlled by how strongly it is diminished by
absorption and scattering in the sample.
For example, although secondary and Auger electrons are
produced throughout the interaction volume, they have
very low energies and can only escape from a thin layer
near the sample's surface. Similarly, soft X-rays, which are
absorbed more easily than hard X-rays, will escape more
readily from the upper portions of the interaction volume.
Absorption is an important phenomenon and is discussed
in more detail below.
![Page 43: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/43.jpg)
Figure 2.1b. Generalized
illustration of interaction volumes
for various electron-specimen
interactions. Auger electrons (not
shown) emerge from a very thin
region of the sample surface
(maximum depth about 50 Å) than
do secondary electrons (50-500 Å).
Interaction volumes
![Page 44: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/44.jpg)
Volume of Excitation
Two factors limit the size and shape of the interaction volume: (1) energy loss through inelastic interactions
and (2) electron loss or backscattering through elastic interactions. The resulting excitation volume is a
hemispherical to jug-shaped region with the neck of jug at the specimen surface. The analyst must remember
that the interaction volume penetrates a significant depth into the sample and avoid edges where it may
penetrate overlapping materials. The depth of electron penetration of an electron beam and the volume of
sample with which it interacts are a function of its angle of incidence, the magnitude of its current, the
accelerating voltage, and the average atomic number (Z) of the sample. Of these, accelerating voltage and
density play the largest roles in determining the depth of electron interaction (Figure 2.2a).
Figure 2.2a. Schematic depiction of the variation of
interaction volume shape with average sample
atomic number (Z) and electron beam accelerating
voltage (Eo). The actual shape of the interaction
volume is not as long-necked since the electron
beam in microprobe analysis has a diameter of about
1 m (see Figure 2.1b).
Electron penetration generally ranges from 1-5 µm with the beam incident perpendicular to the sample. The
depth of electron penetration is approximately (Potts, 1987, p. 336):
For example, bombarding a material with a density of 2.5 g/cm3, about the minimum density for silicate
minerals, with Eo = 15 keV, gives x = 2.3 µm. The width of the excited volume can be approximated by
(Potts, 1987, p. 337):
![Page 45: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/45.jpg)
Both of these are empirical expressions. A theoretical expression for the "range" of an electron, the straight line distance between where an
electron enters and its final resting place, for a given Eo is (Kanaya & Okayama, 1972):
The volume of interaction can be modeled by Monte Carlo simulation. In such models, the likelihood of incident electrons interacting with the
sample and scattering and the angle of deflection are determined probabilistically. X-ray generation depths depend strongly on density and
accelerating voltage (Figure 2.2b.). The results derived from Monte Carlo modeling yield a volume of interaction that is very similar to that
determined by etching experiments. The excited volume is roughly spherical and truncated by the specimen surface. The depth of the center of the
sphere decreases with increasing atomic number of the target.
Figure 2.2b. Comparison of electron paths (top) and
sites of X-ray excitation (bottom) in targets of
aluminum, copper, and gold at 20 keV, simulated in
a Monte Carlo procedure (after Heinrich, 1981).
![Page 46: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/46.jpg)
■:EB uniform irradiation
■:EB uniform
irradiation
DD of a,b,c change due
to EB irradiation at d.DD of a,b,c change
again due to EB
irradiation at e.
a
b
aa
c
bb
d
cc
e
dd
ee
Dose Distribution (DD) Simulation
(2)
![Page 47: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/47.jpg)
L/S(Line & Space)Resist Pattern
HV : 50keV
Dose : 140μC/cm2
L = 50nm P
=100nm
L = 90nm P
=200nm
L =150nm P
=300nm
L = 70nm P
=140nm
![Page 48: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/48.jpg)
10 nm
10 nm Space Width Resist Pattern
HV: 50kV
Resist : ZEP520
![Page 49: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/49.jpg)
Hexagonal Grating(by Spot Scan Writing)
500 dots/100μm- length
30kV
5×10-11A
40μs/dot
![Page 50: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/50.jpg)
DualBeam concept
Electron Beam
Tilt axis
1. Electron Columnfor imaging
2. Ion column for micromachining(and imaging)
![Page 51: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/51.jpg)
Confidential
FEI DualBeams
Quanta 3D and
Helios NanoLab
![Page 52: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/52.jpg)
The Ion Beam
•For the same Beam Energy (as used in SEM) there are big differences in other critical parameters:
•Mass: Ga+ Ion = 128,000 times heavier than Electron
•Velocity: Ga+ Ion = 1/360 of Electron
•Momentum: Ga+ Ion = 360 times Electron
Typical beam parameters
Acceleration voltage (beam energy): 500 V-30 kV
Beam current: 1pA to 20-60 nA
Beam spot: 10 nm spot size at 1pA (300 nm @ 20nA)
![Page 53: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/53.jpg)
Liquid Metal Ion Source (field emission)
The tungsten is wetted
with gallium which is
held in the spiral by
surface tension. The
vapour pressure is
about 10-7 mbar.
Frozen-in-shape LMIS
showing 49o
half angle.
The field emission area
is a 2-5nm across giving
current densities >108
Acm-2.
Electric
field
Taylor
cone of
gallium
![Page 54: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/54.jpg)
Ion Column
Suppressor & LMIS
Extractor Cap
Beam Acceptance Aperture
Lens 1
Beam Defining Aperture
Beam Blanking
Deflection Octupole
Stigmator Lens
Final Lens (Focus)
Lens 2
![Page 55: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/55.jpg)
55
Primary Ion Beam
Implanted Ion
Low energy sputtered
ions and neutralse-
e-e-
e-
e-Vacuum
Solid specimen
Primary ion penetration
depth 20 nm
SE - Secondary Electrons
Ion Beam - Sample Interactions
Ga+ mass is 105 times electron mass
![Page 56: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/56.jpg)
ConfidentialGold particles on carbon Resolution ~6nm
Resolution ~ 5 nm @ 1pA Ion beam current
![Page 57: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/57.jpg)
electrons/ions on target of Aluminium with different energy
30 keV electron
Penetration
depth
1 keV Ga+ ion
Stop Range
30 keV Ga+ ion
Stop Range
1 keV electron
Penetration
depth
6 u
m
50 n
m
30 n
m
6 n
m
![Page 58: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/58.jpg)
58
Sputter Yield in Si as a function of angle and E
0
5
10
15
20
25
30
35
40
0 10 20 30 40 50 60 70 80 90
incidence angle (degrees)
sp
utt
er
yie
ld (
ato
ms/io
n)
Ga 1 keV
Ga 2 keV
Ga 5 keV
Ga 30 keV
channelling
![Page 59: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/59.jpg)
59
Sputter Yield and target materials
Prenitzer et al., M&M 2003
Z=30
Z=14
Z=29
Z=13
Materials
Parameters:
- Atomic number or
mass
- Binding energy
- Crystal structure
(channelling)
- Re-deposition
![Page 60: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/60.jpg)
60
Materials Have Different Sputter Yields
Zinc, Z=30
Copper, Z=29
Aluminum, Z=13
Silicon, Z=14
![Page 61: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/61.jpg)
Gas assisted etch and deposition
Common gases available (etch):
Iodine (silicon)
xenon fluoride (oxide, nitride)
Water (resist, plastic)
Common gases available (depo):
Platinum, Tungsten,
Gold, Iron,
carbon
Silicon oxide…
![Page 62: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/62.jpg)
1. Adsorption of the gas molecules on to the substrate surface
2. Activation of an chemical reaction of the gas molecules by the Ion- / E-beam
3. Generation of volatile reaction- products .
4. Evaporation of volatile species and sputtering of non volatile species
Focused Ion Beam milling and gas assisted etch
![Page 63: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/63.jpg)
63
Iodine Enhanced Etch (IEE)
30 KeV Ion Beam on Silicon
![Page 64: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/64.jpg)
Electron/ Ion Beam Induced deposition (EBID)
Common gases available (depo):
Platinum, Tungsten,
Gold, Iron,
carbon
Silicon oxide…
![Page 65: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/65.jpg)
Confidential
Electron Beam Induced deposition (EBID)
![Page 66: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/66.jpg)
Electron Beam Induced deposition (EBID)
Confidential
![Page 67: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/67.jpg)
![Page 68: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/68.jpg)
1. Adsorption of the precursor molecules on the substrate
2. Ion beam / e-beam induced dissociation of the gas molecules
3. Deposition of the material atoms and removal of the organic ligands
Available on CrossBeams:
Metals: W, PtInsulator: SiO2
Ion Beam Induced deposition
![Page 69: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/69.jpg)
69
• Deposition is a delicate balance between decomposing the adsorbed gas and sputtering.
Ion Beam Induced deposition
Typical W deposition layer composition:
W: 60%Ga: 25%C: 15%
![Page 70: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/70.jpg)
Comparing EBID and FIB deposition
FIB deposition EBID
Deposition rate high low
Substrate milling yes no
Deposition Ga yes no
Purity high lower, current dep
Min size 20 nm 10 nm
![Page 71: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/71.jpg)
Confidential
Overview of DualBeam Applications
Cross Sectioning
Serial Sectioning for 3D reconstruction
Patterning / Micromachining
TEM Sample Preparation
![Page 72: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/72.jpg)
Confidential
Cross SectioningWhat is a Cross section?
FIB removes some material from bulk leaving a trench with a vertical side wall (perpendicular to the surface) revealing the inner sample structure.
SEM collects images of the side wall, with a certain incidence angle
Electron beam
![Page 73: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/73.jpg)
Confidential
A three-step process•1 - Pt Deposition
•2 - Rough Cut
•3 - Polish
1 2 3
![Page 74: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/74.jpg)
Confidential
(Large) Cross Section – End Result
![Page 75: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/75.jpg)
Confidential
Defect Analysis on coating
![Page 76: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/76.jpg)
Confidential
Cross-section of a Hepe filter
Platinum protection strap
Any kind of material: Cellulose
![Page 77: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/77.jpg)
Confidential
Delaminating of layers on helmet’s windshield (polycarbonate)
Any kind of material: Polymers
Defect on surface
![Page 78: Application of Plasmons and fabrication methods Enzo Di ...static.sif.it/SIF/resources/public/files/va2010/difabrizio_0712.pdf · BIONEM group (Bio&Nano engineering for Medicine)](https://reader030.vdocuments.mx/reader030/viewer/2022040401/5e7c29bb758d81731b092c8d/html5/thumbnails/78.jpg)
Confidential
Cross Sectioning: Cryo mode
Cross section of petal’s
flower with the use of
Cryo stage.