Graphene based metrologyJT JanssenNational Physical LaboratoryUK

Workshop “Graphene for future emerging technologies”

Madrid, 18th October 2011

2

Outline

Graphene for metrology

Metrology for graphene Underpin and accelerate innovationPromote trade and cooperation

Enhance sensitivityProliferate quantum standardsUnderpin SI units

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About NPL …

The UK’s national standards laboratory

Founded in 1900

World leading National Measurement Institute

450+ specialists in Measurement Science

State-of-the-art laboratory facilities

The heart of the UK’s National Measurement System to support business and society

Experts in Knowledge Transfer

A very successful GOCO

Managed by Serco since 199535 746 m2

388 Laboratories

Purpose built

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A world without measurement ...

Measurement provides structure, removes chaos, reduces waste, ensures open and fair markets, supports precision

when required, and saves lives, money and time

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What do we do

Develop & disseminate UK’s measurement standards, ensure they are internationally acceptedMultidisciplinary R&D and technical services for public and private sectorKnowledge transfer and advice between industry, government and academiaPromotion of science and engineering

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The growing demand for better measurements

Health & safety

Environment

Healthcare

Manufacturing

Communications

TransportEnergy

Science

2% of GDP dependent on a robust measurement system

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Consistency in measurement

Other NMIsNIST, PTB

Demonstrating equivalence –coordinated by BIPM

• Science• Technology• Data• Facilities

• Documentarystandards

• Training• Knowledge

transfer

Other orgs(e.g. BSI, ISO)

Academia& RTOs

Calibrated instrument, agreed procedure, trained practitioner, (verification)

CalibrationLabs

CalibrationLabs

CalibrationLabs

Ensuring traceability

UK NMIs(NPL, NEL, LGC)

Business, Government, Society

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Artefact standards

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Primary quantum standards

Standards which only depend on the fundamental constants of nature

• Independent of time• Can be generated everywhere in the world• Accuracy only limited by our ability to measure

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Present SI system• The kilogram is the unit of mass; it is equal to the mass of

the international prototype of the kilogram

• The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 x 10-7 newton per metre of length.

• The kelvin, unit of thermodynamic temperature, is the fraction 1/273.16 of the thermodynamic temperature of the triple point of water.

secondmetrekilogramamperekelvinmolecandela

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The quantum Hall effect

iehRH1

2 ⋅=

Discovered in 1980 by Klaus von Klitzing Nobel Prize in Physics in 1985

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Unconventional quantum Hall effect

( )( )214 2+= Nh

exyσ

Novoselov, et al., Zhang, et al., Nature 438, 2005

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Graphene for metrology

New, easy to use quantum resistance standard

Universality test of the quantum Hall effect

• Material independence• Band structure independence• Re-definition of the SI Units

• Higher T • Lower B• QH Arrays

Electron-electron interactionSpin-orbit coupling

Hyperfine interactionGravity

Should have no effect

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Epitaxial Graphene

Rc ≈ 1 Ωµ ≈ 7000 cm-2V-1s-1

W=35 µmL=160 µm

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Charge transfer between epitaxial graphene and SiC

Kopylov et al., APL97, 1112109 (2010)

( )[ ] gsFgs nnnndeA +=−+− επγ 24

A= 0.40 eVd =0.3 nmγ= 5.04x1012 eV-1cm-2

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Photochemical gating

Lara-Avila et al., Advanced Materials, (2011)

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Unconventional breakdown currentν=2

0 5 10 150

5

10

B(T)

ρ xx,ρ

xy (k

Ω)

0

100

200

300

400

500

I(µ

A)

c

TJBMJ et al., Phys. Rev. B 83, 233402 (2011).

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Universality of the quantum Hall effect

87 parts in 1012 Quantum Hall effect –benchmark of the maturity of the 2DEG technology.Graphene quantum Hall resistance standardInternational comparisonPreviously unattainable precision physical experiments.

NPL and collaborators

TJBMJ et al., New J. Phys. 13, 093026 (2011)

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Other quantum standards based on graphene

Single electron transport

NEMS (Force and mass sensors)

THz detectionNanomagnetism (Hall sensors)

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Metrology for graphene

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ITRS Roadmap

Table ERD8 Research and Technology Development Schedule proposed for Carbon-based Nanoelectronics to impact the Industry's Timetable for Scaling Information Processing Technologie

2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023CMOS Extension Devices Graphene Devices

Doping Control

Graphene Epitaxy

Edge Control of Graphene

Bandgap Control of Graphene

Ohmic contacts

Hi-K Gate dielectric & gate metal

Heterobandgap junction structures

Beyond CMOS Devices Graphene Devices Veselago Electron Lens Pseudospintronics Quantum Interference Quantum Hall Effect Bi-layer structures Other platforms include CNT, NEMS and Molecular ElectronicsThis legend indicates the time during which research, development, and qualification/pre-production should be taking place for the solution.

Research RequiredDevelopment UnderwayQualification / Pre-ProductionContinuous Improvement

Narrow Options

s

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Challenges

Metrology away from the lab into the factory

In-line measurement of relevant parameters• structure • mobility • carrier density• homogeneity•

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Analytical techniques

Layers/defects/interfaces/contacts/devicesUniformity of graphene by functional scanning probe microscopyGraphene/substrate interface chemistry and near-surface impurities by 3D mapping.Results on the local scale correlated with transport (incl. contactless) measurements

NPL/Linköping

T. Burnett, R. Yakimova, O. KazakovaNano Letters, 11, 2324–2328 (2011)

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Surface and interface chemical metrology for graphene based electronic devices

Raman and TERSNumber of layers, defects, edge type

Electronic structure

SIMS:Quantify dopant concentration and impurities

>108 atoms/cm2, 1016 atoms/cm3

Identification of contamination, depth profile

SECMElectrochemical mapping (defects, dopants,

functionalisation)

DopantsNH3, alkali atoms,

N2O, H2O, O2and organic molecules

Contaminationlayer

SubstrateSiC, SiO2, Si, PET, h-BN

Defects

Layers

Impurities

Quantification

Sputtering yields

Projectiles and energies

0 50 100 150 200 250 300 350 400 450 500

Depth (nm)

(C33

H 46N

3O5- )

Inte

nsity

(arb

uni

ts)

5 keV

10 keV

20 keV

30 keV

O

-N

ON

N

O

CH2

CH2

OH

OH

0 50 100 150 200 250 300 350 400 450 500

Depth (nm)

(C33

H 46N

3O5- )

Inte

nsity

(arb

uni

ts)

5 keV

10 keV

20 keV

30 keV

O

-N

ON

N

O

CH2

CH2

OH

OH

O

-N

ON

N

O

CH2

CH2

OH

OH

0

100

200

300

400

500

600

700

0 2 4 6 8 10Dose, F (1018 ions m-2)

Dep

th, D

(nm

)

5 keV

10 keV

20 keV

30 keV

0

100

200

300

400

500

600

700

0 2 4 6 8 10Dose, F (1018 ions m-2)

Dep

th, D

(nm

)

5 keV

10 keV

20 keV

30 keV

( ) ( )( )FSSFSD DSDS

σσ

−−−

+= ∞∞ exp10

0

5

10

15

20

25

30

35

40

0 2 4 6 8 10

Dose, F (1018 ions m-2)

Rq

(nm

)

30 keV20 keV

10 keV

5 keV

0

5

10

15

20

25

30

35

40

0 2 4 6 8 10

Dose, F (1018 ions m-2)

Rq

(nm

)

30 keV20 keV

10 keV

5 keV

0

0.5

1

1.5

2

2.5

0 100 200 300 400 500

Depth (nm)

Vol

ume

fract

ion

Irgan

ox31

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X(3114)

QCM

A

B

C

D

E

I(564 u) S -2

I(346 u) S -2

I(26 u) S -1

Rotation and coolingDose (1018 ions m-2)

0 1 2 3 4 5 6

Dose (1018 ions m-2)

Inte

nsity

(564

u)

0 0.5 1 1.5

Dose (1018 ions m-2)

Inte

nsity

(564

u)

Participant L: 10 keV, 45°, -80°C

Participant E: 20 keV, 45°, rotation

b

cP Sjövall et al.,J. Phys. Chem. B, 2010, 114, 769 0

2468

101214161820

A B C D E F G K L M O Q R T

Participant

RS

D (%

)

Repeatabilityand reproducibility

A G Shard et al., Surf. Interface Anal. DOI: 10.1002/sia.3268

Novel ion beamsAr500-1000 clustersJ L S Lee et al., Anal. Chem. 2010, 82, 98

Incidence angle

0 0.5 1 1.5 2 2.5 3 3.5

Inte

nsity

(564

u) Participant S: 20 keV, 76°a

S. Iida et al., e-J. Surf. Sci. Nanotech. 2009, 7, 878AG Shard et al, J Phys Chem B 112 (2008) 2596

A Shard et al, JPC B 112 (2008) 2596

A Shard et al, JPC B 112 (2008) 2596

NPL developed delta layer to study fundamentals of cluster ion beam sputtering

Depth resolution

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Slide courtesy of Wilfried Vandervorst, IMEC

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Electron Spectroscopies for Graphene

Emtsev, PRB 77, 155303 (2008)

Wang, APL 95, 063302 (2009)

Techniques:• XPS, UPS (at NPL)• PEEM, NEXAFS (Diamond)• ARPES (Diamond)

Information:• Quantitative chemical analysis• Work function• Band structure

Si terminated SiC

C terminated SiC

Pacile, PRL 101, 066806 (2008)

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Summary

•We are able to deploy the arsenal of quantum electrical metrology, functional scanning probe microscopy and 3D nano-analysis to support the development and application of graphene electronic devices capable to sustain and extend performance scaling substantially beyond the fundamental limits of conventional technologies.

•There is an opportunity to capitalise on the European lead in graphene, metrology/science to underpin the emerging graphene industry with confidence in the potential of this material.

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Co-workersAlexander Tzalenchuk, Olga Kazakova, Jonathan Williams, Ian Gilmore, Alex Shard, Tim Burnett (NPL)Sergey Kubatkin, Samuel Lara-Avila, Alexei Kalaboukhov, Karin Cedergren (Chalmers)Sara Paolillo (Milan)Mikael Syväjärvi, Rositza Yakimova (Linköping)Sergey Kopylov, Vladimir Fal'ko (Lancaster)Nick Fletcher, Roland Goebel (BIPM)

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Thank You

www.npl.co.uk