IEE5328 Nanodevice Transport Theory and Computational Tools

Prof. Ming-Jer ChenDept. Electronics EngineeringNational Chiao-Tung UniversityFeb. 20, 2013

Lecture 1:

Introduction

1IEE5328 Prof. MJ Chen NCTU

Can we survive in the highly-challenging but widely-controversial future?

IEE5328 Prof. MJ Chen NCTU 2

Motivation of this Nano Course

- Advanced Device Physics

- Hands-on Calculations

IEE5328 Prof. MJ Chen NCTU 3

Two Elements of the Course

• Industry Compatible

• ITRS Oriented

• Covering FETs down to 3-nm node

4

ITRS : International Technology Roadmap for Semiconductors

Three Features of the Course:

IEE5328 Prof. MJ Chen NCTU

IEE5328 Prof. MJ Chen NCTU 5

6

FETs Down-Scaling

IEE5328 Prof. MJ Chen NCTU

7

Polysilicon Gate Bulk Planar Extension• Strained Silicon Channel• Substrate/Channel Orientation

IEE5328 Prof. MJ Chen NCTU

8

High-k Metal Gate Bulk Planar Extension• Strained Silicon Channel• Substrate/Channel Orientation

IEE5328 Prof. MJ Chen NCTU

9

• Strained Silicon/Germanium/GaAs Channel• Substrate/Channel Orientation• Rsd issue

High-k Metal Gate FinFETs or Multi-Gate FETs

PlanarStructure

VerticalStructure

IEE5328 Prof. MJ Chen NCTU

TSMC 10, 14, and 16 nm

TSMC 20 nm

IEE5328 Prof. MJ Chen NCTU 10

ITRS Roadmap

11

High-Performance NanoFETs projected by ITRS 2011 (http://www.itrs.net)

(Bulk and SOI)

IEE5328 Prof. MJ Chen NCTU

12

High-Performance FETs projected by ITRS 2011 (http://www.itrs.net)

(Bulk and SOI)

IEE5328 Prof. MJ Chen NCTU

13

High-Performance FETs projected by ITRS 2011 (http://www.itrs.net)

(Multi-Gates and SOI)

IEE5328 Prof. MJ Chen NCTU

14

High-Performance FETs projected by ITRS 2011 (http://www.itrs.net)(Multi-Gates and SOI)

IEE5328 Prof. MJ Chen NCTU

15

Low-Power NanoFETs projected by ITRS 2011 (http://www.itrs.net)

(Bulk, SOI, and Multi-Gates)

IEE5328 Prof. MJ Chen NCTU

16

Low-Power NanoFETs projected by ITRS 2011 (http://www.itrs.net)

(Bulk, SOI, and Multi-Gates)

IEE5328 Prof. MJ Chen NCTU

17

• EOT down to around 0.5 nm

- Tunneling - Additional Mobility Degradation

• Feature Size (Channel Length) down to 3 nm

- Non-equilibrium Transport - DIBL Penetration - Tunneling

Two Key Projections by ITRS:

Printed Gate Length: as in layout phasePhysical Gate Length Lg: post-processing as determined by TEM or C-V fittingChannel Length L: Physical Gate Length Lg minus 2 times the overlap extension Lov

IEE5328 Prof. MJ Chen NCTU

The Purposes of the Course:

-Provide Advanced Device Physics for a working nanoFET

-Capture Key Points behind nanoFETs data and structures, simply through hands-on calculations

18IEE5328 Prof. MJ Chen NCTU

You will do during this course:

-Capture Advanced Device Physics

-Read good papers

-Derive models and do calculations, given TCAD and/or experimental data

- Also run TCAD

-Establish Physical Pictures of your own 19IEE5328 Prof. MJ Chen NCTU

Course Contents

20IEE5328 Prof. MJ Chen NCTU

• MOS Energy Band Diagrams

• C-V

• Defects, Oxygen Vacancies

• Tunneling Paths

• Models, TCAD, Experimental Data, Calculation, and Fitting

1. High-k Metal-Gate Stacks: MOS Electrostatics

21

2. High-k Metal-Gate FETs: Channel Mobility• Quantum Confinement

• Band Structure

• Coulomb Impurity Scattering, Phonon Scattering, Surface Roughness Scattering

• Remote Interface Plasmons Scattering, Remote Coulomb (Defects) Scattering, Remote Soft Phonon Scattering

• Models, TCAD, Experimental Data, Calculation, and FittingIEE5328 Prof. MJ Chen NCTU

• Energy Band Diagrams

• Tunneling Paths

• Models, TCAD, Experimental Data, Calculation, and Fitting

3. Band-to-Band Tunneling

22

4. Ballistic and Backscattering in Channel• Energy Band Diagrams

• 2-D versus 1-D

• Models, TCAD, Experimental Data, Calculation, and Fitting

IEE5328 Prof. MJ Chen NCTU

• Energy Band Diagrams

• Ballistic Mobility

• Scattering by Highly-Doped Source/Drain Plasmons

• Source Starvation

• Models, TCAD, Experimental Data, Calculation, and Fitting

5. Degraded Mobility and Saturation Current with Shrinking L

23

6. Threshold Roll-off and DIBL Penetration (Electrostatics from Source and Drain)

• Energy Band Diagrams

• 2-D versus 1-D

• Models, TCAD, Experimental Data, Calculation, and Fitting

IEE5328 Prof. MJ Chen NCTU

• Ultrathin Source/Drain Extension Junction

• Components of Series Resistance Rsd

• Models, TCAD, Experimental Data, Calculation, and Fitting

7. Other Issues of Significance - I

24

8. Other Issues of Significance - II• Alternative Channel Materials: Ge, GaAs, and Graphene

• Models, TCAD, Experimental Data, Calculation, and Fitting

IEE5328 Prof. MJ Chen NCTU

•Lecture Notes, Prof. Ming-Jer Chen, 2013.

•Literature Papers

25

Course Material to be Delivered:

IEE5328 Prof. MJ Chen NCTU

Taken-Home Works and Reports Only

26IEE5328 Prof. MJ Chen NCTU

Grading