Schottky Contact Revisited · 1D-NEON: Fibre based printed devices (oTFT and oLED) for wearable...

Copyright © 2019 Silvaco Inc.

R1

FROM ATOMS TO SYSTEMS

Schottky Contact Revisited

IEEE EDS Workshop 2019, Orme des Merisiers

P. Blaise, PhD, Sr. AE atomistic [email protected]

Copyright © 2019 Silvaco Inc. Copyright © 2019 Silvaco Inc.

2

• TCAD flow: Silvaco environment

•Ab initio: 2D-TMD / Metal contact.

• Atomistic TCAD: Victory Atomistic, a new-comer.

PLAN





SILVACO Inc.

Austin, US

Sales

Seoul, KP

Sales

Boston, US

Sales

Grenoble, FR

Sales, R&D

Kyoto, JP

Sales

Cambridge, GB

Sales, R&D

Vienna, AT

R&D

Silicon Valley, US

HQ, R&D, Sales

Moscow, RU

R&D

Copenhagen, DK

R&D

Singapore, SG

Sales

Shanghai, CN

Sales

Shenzhen, CN

Sales

W. Lafayette, US

R&D

Yokohama, JP

Sales


4

Benefits of TCAD

• In order to reduce the development time and costs of semiconductor technologies. The ITRS roadmap indicates that TCAD simulation can reduce the costs of the development cycles by ~30%.

• You can see “inside” the device. Measurements tell you “what” happens, not “why” it happens, TCAD provides the “why” answers.

• You can experiment with the causality of effects If your device exhibits an unexpected characteristic, you can experiment with various theories in TCAD. If one theory matches the measured result, there is a good chance you have found the cause.

• Improves internal company communication Device modifications and their expected effects can be visualized and passed between departments.


Silvaco TCAD Design Flow

Structure Builder, Process Simulation

Victory Process

Device Simulation

Victory Device

3D RC Extraction

Clever

Layo

ut

Automation and Optimization

2D/3D Visualization

Silvaco TCAD Design FlowTCAD Layout Driven Framework for FEOL and BEOL Simulation Solution.

All in one environment, no need to learn and use multiple tools


6

- 6 -

Wide TCAD Adoption Across Applications


7

Process Simulation

TU Vienna

6 Ph.Ds, for performance improvement of level-set based 3D physical etching, deposition and

oxidation, SiC & GaN process simulation

EU Funded ProjectsDOMINO: Scientist exchange project focused on the

development of compact models for organic and oxide SC based large area electronics (LAE).

ALMA: multiscale modelling of thermal transport in semiconducting materials. Link Boltzmann Transport Equations

(BTE) to TCAD.

Challenge: The development of 3C-SiC based power electronic devices. From growth to device modelling.

1D-NEON: Fibre based printed devices (oTFT and oLED) for wearable electronics.

EXTMOS: Multiscale modelling of organic based TFTs and LEDs from DFT to SPICE.

COST: Multiscale modelling of solar cells.

Device Simulation

TU Vienna 3 Ph.Ds, for advanced MRAM device simulation

MIT 3D GaN FinFET

RIT Design Strategies for Ultralow Power 10nm node FinFETs

UC Davis GaN Device simulation

ASU Diamond-based Device simulation

Kent University Ion transport modeling (Organic Electrochemical transistors)

Projects in preparation

LETI: Nanowire and GaN spice compact model

IMEC: Cryogenic TCAD and modeling Project

Collaborations


Plan





9

My Dipole is a Microscopic Average

(a0)

(e/a

03)

Métal W vide

• Solve the microscopic 3D Poisson equationthanks to a DFT ab initio calculation

+ -

e- spill-out

W slab • After a 2D average procedure, the oscillations related to successive atomicplanes are filtered by several convolutions leading to a macroscopic averaged 1D Poisson equation


10

M-S JUNCTION

m-elec. Solid State Vacuum

• PRB 64 205310, R. Tung: « Formation of an electric dipole at metal-semiconductor interfaces »

• The central quantity is the band offset

Which gives two definitions for the dipole that are related by


11

2D TMD Contact

Top Oxide

Back Oxide

Silicon (Back-gate)

S D

Rext

G

t2D

2D Mat.

- - - - - -+ + + + + +

Interface charge transfer

0.3 1 10 1000

0.5

1

1.5

2

2.5

thickness (nm)

Eg (

eV) GaAs

Si

Ge

InAs

InSb

2DTMDs

tsemi (nm)

3D

E G(e

V)

C. English, E. Pop et al., Nano Lett., (2016)• 3D materials → nanometer scale restricts

band gap and carrier mobility

• 2D solution → atomically thin materials

Transition Metal Di-chalcogenides (ex: MoS2)


12

2D TMD - Metal Dipole

S. V. Suryavanshi et al., IEEE SISC, 2017, 2018, San Diego, CA

• Metal 2D reactivity modulates VdW gap and FB

• DFT simulation: full relaxation with residual strain on metal

• Simulation of FB engineering:

• Point defects

• Impurities

• Intercalation layer


13

2D/Metal Dipole modulation

• Point defect effect on FB is screened by Ti reactivity

• S and Mo effects suggest to intercalate a 2D layer

• Au contact• Ti contact

Eg

FB

(eV

)

FB

(eV

)


14

2D Intercalation layerMetal contact

(hcp-Ti)

TiTe2

Bottom MoS2

(reference)

• Ti contact • Au contact

• P+ : Ti or V substitutes Mo

• N+: Te or Se substitutes S

• 2D intercalation layer stability


15

2D / Metal – Contact ResistanceR

C(Ω·μ

m)

n2D (cm-2)

Ti

Au Gr.

Au Ti

Au Gr.

Ag • Fundamental limit to RC < 10 Ω·μm

• Metal-2D interface has poor transmission

• Reduce the vdW gap and reduce the FB

(follow the ab initio work on interfaces)

• Can we go a step further?

• Quantum transmission:

S. V. Suryavanshi PhD Thesis (Stanford U., E. Pop group)

www.nanohub.org


Plan





17

Victory Atomistic: Nemo5 Pro

Silvaco, Purdue Team Up to Bring Scalable Atomistic TCAD Solutions For Next Generation Semiconductor

Devices And Materials

“The NEMO tool suite represents the spearhead of nanotechnology modeling –both for well-controlled experimental conditions as well as large-scale fabricationreality. Its commercial version, customized to industrial needs and infrastructure,will have high societal impact”, T. Kubis, see:

https://www.purdue.edu/newsroom/releases/2018/Q3/silvaco,-purdue-team-up-to-bring-scalable-atomistic-tcad-solutions-for-next-generation-semiconductor-devices-and-

materials.htmlhttps://www.silvaco.com/news/pressreleases/2018_08_24_01.html

https://www.purdue.edu/newsroom/releases/2018/Q3/silvaco,-purdue-team-up-to-bring-scalable-atomistic-tcad-solutions-for-next-generation-semiconductor-devices-and-materials.html

https://www.silvaco.com/news/pressreleases/2018_08_24_01.html


18

Atomistic Contact Resistivity

NiSi p-Si Contact resistivity as a function of doping for transport along [100], [110] and [111] crystal direction. Transport along [111] offers the lowest resistivity due to the smaller light hole effective mass and higher transverse density of states.


R1

FROM ATOMS TO SYSTEMS

Thank you for your attention!

Schottky Contact Revisited · 1D-NEON: Fibre based printed devices (oTFT and oLED) for wearable...

Documents

Transcript of Schottky Contact Revisited · 1D-NEON: Fibre based printed devices (oTFT and oLED) for wearable...