Transcript
Page 1: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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2D Materials for Ubiquitous Electronics

Saptarshi Das

Assistant ProfessorEngineering Science and Mechanics

Materials Research InstitutePennsylvania State University

[email protected]

2DCC-MIP Webinar September 7, 2017

Page 2: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Traditional Electronics

Page 3: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Transistor Evolution

Gate

Source Drain

Oxide

VGS

VDS

Substrate

Si

4 decadesโ€“ 4 orders of magnitude length scaling

100ยตm 197510nm 2015

Source Drain

ฮปS

Short Channel LimitLCH > 3ฮปS

๐œ†๐‘† = ๐œ†๐‘”๐‘’๐‘œ =๐œ€๐‘๐‘œ๐‘‘๐‘ฆโˆ’๐‘ฅ

๐œ€๐‘œ๐‘ฅ๐‘ก๐‘๐‘œ๐‘‘๐‘ฆ๐‘ก๐‘œ๐‘ฅ

tbody โ‰ˆ 6nm ฮปS โ‰ˆ 4.2nmSi FinFET

Scaling Ends โ€“ Doomsday ?

Page 4: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Gate

Source Drain

Oxide

VGS

VDS

Substrate

2D Materials can rescue!!

Source Drain

ฮปS

Short Channel LimitLCH > 3ฮปS

tbody โ‰ˆ 0.65nm ฮปS โ‰ˆ 1.4nmMonolayer MoS2

tMoS2 = 0.65 nm

๐œ†๐‘† = ๐œ†๐‘”๐‘’๐‘œ =๐œ€๐‘๐‘œ๐‘‘๐‘ฆโˆ’๐‘ฅ

๐œ€๐‘œ๐‘ฅ๐‘ก๐‘๐‘œ๐‘‘๐‘ฆ๐‘ก๐‘œ๐‘ฅ

tbody โ‰ˆ 6nm ฮปS โ‰ˆ 4.2nmSi FinFET

Transistor Evolution

Page 5: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Monolayers are Essential

Gate

Source Drain

Oxide

VGS

VDS

Substrate

Large Bandgap (1.8eV)

Schottky Barrier Contact1T-phase contact (200ฮฉ-ยตm)

Bandgap EngineeringStraintronics

Ballistic LimitNo Concerns

Quasi Ballistic Low mobility โ€“ No problem

h-BN buffer layer

Monolayer Mobility is poor

Transistor Evolution

Page 6: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Current State of AffairsCVD, MOCVD, MBE Growth

Kang. K, et al., Nature, 520, 656โ€“660, 2015.

van der Zande. A. M, et al., Nature Materials, 12, 554โ€“561, 2013.

Transistor Evolution

Future looks promising

Desai. B. S, et al., MoS2 transistors with 1-nanometer gate lengths. Science, 354, 6308, 99-102

Page 7: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Power Dissipation

ฮ”VTH

ฮ”IOFF

Gate

Source Drain

Oxide

VGS

VDS

Substrate

Boltzmann Tyranny

Voltage Scaling Almost Stopped

Fundamental Limitations at Device Level

Innovation in Device Physics

๐‘บ๐‘บ =๐’Œ๐‘ฉ๐‘ป

๐’’๐’๐’๐Ÿ๐ŸŽ

Page 8: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Power Dissipation

Gate

Source Drain

Oxide

VGS

VDS

Substrate

Boltzmann Tyranny

Voltage Scaling Almost Stopped

Fundamental Limitations at Device Level

Innovation in Device Physics

๐‘บ๐‘บ =๐’Œ๐‘ฉ๐‘ป

๐’’๐’๐’๐Ÿ๐ŸŽ

ฮ”VTH

ฮ”IOFF

Page 9: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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A Novel Concept: 2D EFET

Two Dimensional (2D) - Electrostrictive Field Effect Transistor

Das. S; Two Dimensional Electrostrictive Field Effect Transistor (2D-EFET). Scientific Reports, 6, 34811, 2016.Ultra Low Power FET

Monolayer MoS2 undergoes SMT at 3GPaAlvarez. M, et al. Nano Letters, 15 (5), 3139โ€“3146, 2015.

Page 10: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Source Drain

Source Drain

ฮจS

VDDEG0

๐œณ๐‘ฌ = โˆ’๐œถ

๐Ÿ๐‘ท

๐‘ท๐Ÿ๐‘ซ = ๐œผ๐‘ช๐Ÿ‘๐Ÿ‘,๐Ÿ๐‘ซ๐Ÿ

๐’•๐Ÿ๐‘ซ๐’…๐Ÿ‘๐Ÿ‘๐‘ฝ๐‘ฎ๐‘บ

VB

Electrostrictive/

Piezoelectric

Material

Substrate

2D Semiconductor

Gate

Dielectric

So

urc

e

Dra

in

VDD

VGS

Capping

Layer

Back Contact

๐๐‘ฌ = ๐œผ ๐œถ๐‘ช๐Ÿ‘๐Ÿ‘,๐Ÿ๐‘ซ๐Ÿ

๐Ÿ๐’•๐Ÿ๐‘ซ๐’…๐Ÿ‘๐Ÿ‘ ๐‘ฝ๐‘ฎ๐‘บ๐๐‘บ = ๐‘ฝ๐‘ฎ๐‘บ ๐œ“๐‘‡ = ๐‘‰๐บ๐‘†(1 + ๐œ‚๐›ฝ๐‘‘33)

EG

ฮจE

๐œณ๐‘บ = ๐’“๐‘ฝ๐‘ฎ๐‘บ ๐’“ โ‰ค ๐Ÿ

Stiffness: ๐‘ช๐Ÿ‘๐Ÿ‘ (GPa)

Piezoelectric Coefficient: ๐’…๐Ÿ‘๐Ÿ‘ (pm/V)

Eg Coefficient: ๐œถ (meV/GPa)

Strain transfer coefficient: ๐œผA Novel Concept: 2D EFET

Ultra Low Power FET

Page 11: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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๐ผ1 =2๐‘ž

โ„Žเถฑ๐‘€ ๐ธ ๐‘‡ ๐ธ ๐‘“๐‘  ๐ธ ๐‘‘๐ธ

๐ผ2 =2๐‘ž

โ„Žเถฑ๐‘€ ๐ธ ๐‘‡ ๐ธ ๐‘“๐ท ๐ธ ๐‘‘๐ธ

Source

Drain

VDD

๐‘‰๐น๐ต โˆ’ฮจ๐‘‡

๐‘‰๐น๐ต โˆ’ฮจ๐‘‡ + ๐‘‰๐ท๐ท

๐ผ1 ๐ผ21

1

๐ผ = ๐ผ1 โˆ’ ๐ผ2

Solid: ๐œ‚ = 0Dashed: ๐œ‚ = 0.3

๐‘‰๐ท = 100๐‘š๐‘‰

SS = 60mV/decade

โŠฅMoS2 Compliance:๐ถ33 = 60 ๐บ๐‘ƒ๐‘Ž

Piezoelectric Coefficient: ๐‘‘33 = 850 ๐‘๐‘š/๐‘‰

MoS2 Eg Coefficient: ๐›ผ = โˆ’80๐‘š๐‘’๐‘‰/๐บ๐‘ƒ๐‘Ž

๐œ“๐‘‡ = ๐‘‰๐บ๐‘†(1 + ๐œ‚๐›ฝ๐‘‘33)

Schulman. S. D, et al. manuscript inpreparation 2017.

A Novel Concept: 2D EFET

Ultra Low Power FET

Page 12: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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MotivationTrimming the high energy Fermi tail results in sub-

60mV/decade SS

๐ผ๐‘‚๐‘ โˆ ๐‘‡๐‘Š๐พ๐ต = ๐‘’๐‘ฅ๐‘(โˆ’4

3โ„2๐‘š๐‘’๐ธ๐บ๐œ†)

๐‘‡๐‘Š๐พ๐ต = exp(โˆ’4

3โ„2๐‘š๐‘’๐ธ๐บ๐‘‘๐‘‚๐‘‹๐’…๐‘ฉ๐‘ถ๐‘ซ๐’€)

Band to Band Tunneling

EG

ฮป

OFFEG

ON

ฮป VGS

Das. S, et al. Towards Low Power Electronics: Tunneling Phenomenon in

TMDs ACS Nano, 8(2), 2014.

Tunneling FETsTMDs

Sarkar, D. et al. Nature 526, 91-95, 2015

๐‘บ๐‘บ =๐’Œ๐‘ฉ๐‘ป

๐’’๐’๐’๐Ÿ๐ŸŽ

Ultra Low Power FET

Page 13: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Excitonic Device

Formation of excitonic condensate in spatially separated nanosheets (n-type and p-type) controlled by gate voltage

ON State: SuperconductorOFF State: Normal Semiconductor

ON State: Normal Semiconductor OFF State: Perfect Insulator

Excitonic FETExtreme Energy Efficient Electronics

h-BN

Oxide

N-type Nanosheet

P-typeNanosheet

Oxide

Source

Drain

Co

mm

on

Te

rmin

al

Top Gate

Bottom Gate

e e e e

h h h h

Page 14: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Sensor Electronics

Page 15: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Internet of Things

Sensors

Electrical Mechanical Optical Thermal Chemical Biomedical

High Performance โ€“ No Low Power/Self Power โ€“ YesLow Cost โ€“ Yes

Flexible โ€“ Yes Light Weight โ€“ YesTransparent โ€“ Yes

Page 16: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Flextronics

Metal: Graphene Insulator: h-BN Semiconductor: WSe2

Electron BranchMobility: 24 cm2/V.sON/OFF : 2x107

Hole BranchMobility: 45 cm2/V.sON/OFF : 7x107

Das, S. et al. All Two Dimensional, Flexible, Transparent and Thinnest Thin Film Transistor.

Nano Letters 14 (5), 2014Displays

Thinnest Transistor

Page 17: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Glasstronics

Page 18: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Wu, W. et al. Nature 514, 470-474, 2014Zhu, H. et al. Nature Nanotechnology 10, 151-155, 2015

Piezotronics Self PoweredElectronics

Page 19: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

PhotodetectorIph

p n

hฯ…

Electroluminescence (LEDs)hฯ…

p

n

hฯ…

Photovoltaic (solar cells)Isc,Voc

p n

hฯ…

Electrostatically doped WSe2 p-n diodes

Baugher. et al. Nature Nanotechnology 9, 2014.Ross. et al. Nature Nanotechnology 9, 2014.

Pospischil. et al. Nature Nanotechnology 9, 2014.

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EQE of up to 15% Photoresponsivity of 5x108A/W

Optoelectronics PhotodetectorsSolar Cells

LEDs

Page 20: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Integrated circuit based on MoS2

Wang, H. et al. Nano Letters 12(9), 2012

Memory transistor with MoS2

Lee, H. S. et al. Small 8(20), 2012MoS2 FET based gas-sensor

Sarkar, D. et al. ACS Nano 8(4), 2014

Late, D. J. et al. ACS Nano 7(6), 2013

MoS2 FET based bio-sensor

Integrated CircuitsMemory Transistor

All Purpose ElectronicsBio-SensorsGas-Sensor

Page 21: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Harsh Environment Electronics

Page 22: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Space Electronics

Van Allen Beltsโ€ข Protonsโ€ข Electrons

Cosmic Raysโ€ข Protons (90%)โ€ข Helium Nuclei (9%)โ€ข Electrons (<1%)โ€ข Heavier Ions (<1%)

Van Allen Belts

Cosmic Rays

Inner Belt

Outer Belt

Horne, R. Nature Physics (2007)

Page 23: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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2MeV proton: 1014 protons/cm2 390keV He: 2x1015 ions/cm2 390keV He: 1016 ions/cm2

Arnold, A. et al.; Radiation Effect on MoS2 FETs. unpublished, 2017.

Radiation Exposure Courtesy: Prof. Jovanovic Group (UMich)

Space Electronics

Page 24: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Anticorrosion Electronics

Electrochem Magic

Das. S, et al. A Self-Limiting Electro-Ablation Techniquefor the Top-Down Synthesis of Large-Area MonolayerFlakes of 2D Materials. Scientific Reports, 6, 28195, 2016.

19th Century Electrochemistry Set-upRoom TemperatureRequires Seconds

MoS2

WS2

MoSe2

Exfoliated Multilayer Electroablated Monolayer

Schulman. S. D, et al. Superior Electro-Oxidationand Corrosion Resistance of Monolayer TransitionMetal Disulfides. manuscript under review, 2017.

Huang. Y, et al. An Insight of Electro-AblationProcess for the Synthesis of Monolayer TransitionMetal Diselenides . manuscript under review, 2017.

Page 25: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Extreme Stability/Corrosion Resistance of Monolayer TMDs

Electro-ablation

Page 26: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Electro-ablated MoS2 Monolayers

Raman Photoluminescence

SAED TEM

in-situ spectroscopy In progress: Prof. Emilie Ringe (Rice)

Page 27: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Anticorrosion Monolayer FETs

Schulman. S. D, et al. FETs based on Monolayer Electroablated 2DMaterials. manuscript in preparation, 2017.

Page 28: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

VD = 2V

VD = 4V

VD = 6V

VD = 8V

VD = 10V

VG = -50V

OFF State Stressing

Negative VT shift Quick device recovery

VD = 2V

VD = 4V

VD = 6V

VD = 8V

VD = 10V

ON State Stressing

Negative VT shift Abrupt changes at VD = 10V Slow device recovery

Curiosity Driven Stressing

VD = 10V

VD = 12V

VD = 14V

VD = 16V

VD = 18V

Positive VT shift Abrupt changes at VD = 18V Permanent device damage

Reliable Electronics

Hot Electron Transistor

Arnold, A. et al.; Radiation Effect on MoS2 FETs. unpublished, 2017.

Page 29: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Electron becomes HOT

โ€œLuckyโ€ electron

electron trapping in the gate oxide

positive VTH shift

โ€œLuckyโ€ hole

Hot Carrier Transport

Source

Drain

EG = 1.84

hole trapping in the gate oxide

negative VTH shift

๐‘‰๐‘‡ = ๐‘‰๐น๐ต โˆ’๐‘„๐ผ๐‘‡๐ถ๐‘œ๐‘ฅ

โˆ’๐‘„๐น๐ถ๐‘œ๐‘ฅ

โˆ’๐‘„๐‘€๐ถ๐‘œ๐‘ฅ

โˆ†๐‘‰๐‘‡= โˆ’โˆ†๐‘„

๐ถ๐‘œ๐‘ฅ

momentum randomizing

collision

Impact Ionizatione-h pair generation

Avalanche

Page 30: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

30

Brain Inspired Electronics

Page 31: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Neuron

Soma

Axon

Dendrite

Axon Terminal

Chemical Synapse

Neurotransmitter

Act

ion

Po

ten

tial

t

Immediate Action: Muscle Movement, Chemical SecretionLong-term Action: Memory, Learning

Page 32: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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nAP = 1 nAP = 4

PSCMPSC

Neurotransmitter Release

Bipolar

Excitatory: GlutamateInhibitory: GABA

Quantal

๐‘ƒ๐‘†๐ถ โˆ ๐‘›๐‘‡๐‘“ ๐‘›๐ด๐‘ƒ

Stochastic

๐‘ƒ๐‘†๐ถ โˆ ๐‘๐‘Ÿ๐‘›๐‘‡๐‘“ ๐‘›๐ด๐‘ƒ

Arnold, A. et al.; Mimicking Neurotransmitter Release in Chemical Synapses via Hysteresis Engineering in MoS2 Transistors. ACS Nano, 11, 3110-3118, 2017

Page 33: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Source

Drain

MoS2

2ยตm

VGS = 10V:10V:60V VDS = 1.0V

VDS = 0.8V

VDS = 0.6V

VDS = 0.4V

Low

DIBL

ยตn = 20cm2/V.s

VTH

Source Drain

VDS

Back Gate Oxide

P-Doped Si

VGS (Synaptic Input)

IDS (PSC)

Neuromorphic Transistor

Page 34: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

34

Hysteresis Engineering

VP = 60V

VP = 40V

VP = 20V

VTH-BW

VTH-FW

TS = 6s

TS = 12s

TS = 38s

VTH-BW

VTH-FW

Page 35: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

35

Origin of Hysteresis

Page 36: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Inhibitory Response

Excitatory Response

Neuromorphic Transistor QuantalStochasticBipolar

Page 37: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Neuromorphic Transistor

Quantal: Pulse FrequencyStochastic: Pulse MagnitudeBipolar: Pulse Polarity

Source Drain

VDS

Back Gate Oxide

P-Doped Si

VGS (Synaptic Input)

IDS (PSC)

Arnold, A. et al.; Mimicking Neurotransmitter Release in Chemical Synapses via Hysteresis Engineering in MoS2 Transistors. ACS Nano, 11, 3110-3118, 2017

Page 38: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

38

Summary

2D materials can reinstate transistor scaling

2D Materials support novel low power device concepts like EFET, TFET and ExFET

2D Materials are promising for all purpose sensors

2D Materials can be used for harsh environment electronics

2D Materials can be used for brain inspired electronics

Page 39: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

39

Acknowledgement

Graduate Students Daniel SchulmanAndrew ArnoldJoseph NasrYu Ting Huang (visiting)Amritanand SebastianDrew Buzzell

Faculty CollaboratorDr. Mauricio Terrones (PSU)Dr. Nasim Alem (PSU)Dr. Joshua Robinson (PSU)Dr. Susan Trolier-McKinstryDr. Sumeet GuptaDr. Sukwon Choi (PSU)Dr. Emilie Ringe (Rice)

Page 40: 2D Materials for Ubiquitous Electronicsโ‚ฌยฆย ยท Trimming the high energy Fermi tail results in sub-60mV/decade SS ๐ผ โˆ ๐พ = ๐‘ฅ (โˆ’ 4 3โ„ 2 ๐ธ ๐œ†) ๐พ =exp(โˆ’ 4 3โ„

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Thank You


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