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Synopsys Topography Simulations

The Second Quantemol Workshop

Synopsys

London, November 7, 2012

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Outline

Sentaurus Topography 3D introduction

SPTOPO3D project setup

Input file for the built in Ionmill model

Input file for the RFM sputtering model

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What is TCAD ?

Process Simulation

LDMOS: doping, mesh

1D doping profile simulation

PDE for Pair Diffusion

Mechanical stress in intermetal dielectric

Emulation of 4 CIS cells

PVD (Physical Vapor Deposition)

Device Simulation

Current in Drift-Diffusion Model

Potential distribution in flash memory

Snapback of a UMOS

EM Wave

Inductance Simulation

AlGaAs VCSEL Full Chip H-Bridge

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Sentaurus TCAD Product Line

Process

Simulation

Sentaurus Process Framework

Sentaurus

PCM

Studio

Sentaurus Topography

Structure

Editing Sentaurus Structure Editor

Device and

Interconnect

Simulation

Sentaurus Device

Raphael

Sentaurus Interconnect

Sentaurus

Visual

Sentaurus

Workbench

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Sentaurus Topography Main Features

• 2D and 3D feature-scale profile simulator, levelset-based

• Built-in empirical models:

– Deposition: LPCVD, PVD, HDP, Electroplating

– Etching: RIE, HDP, Ion-enhanced

• Including physical effects of sputtering, re-emission, re-deposition, and ion reflection

• Input particle flux defined by IAD

• Surface reaction model (2D)

• Programmable Model Interface (PMI, C++)

• User Rate Formulation Model (RFM)

• Integrated with Sentaurus Process and Sentaurus Interconnect

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• Sentaurus Topography 3D is a three-dimensional simulator for evaluating and optimizing critical topography-processing steps such as etching and deposition

• It simulates deposition and etching processes by using the level-set method to evaluate the boundary evolution during the process

• Models categories: – Built-in models

– User-defined models within Rate Formula

Module (RFM)

– User-defined models within a Physical

Model Interface (PMI)

• Support of different reaction species,

different fluxes, re-deposition, …

Sentaurus Topography 3D

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Sentaurus Topography 3D

• Etching (10 models) – Dry etch, Etchdepo, Etchdepo2, HDP, HDP2, Ion_enhanced, Ionmill, Rie, Rie2,

Simple…

• Deposition (7 models) – HDP, HDP2, LPCVD, PECVD, PVD, Simple, Electroplating…

• Rate Formula Module (RFM)

• Ion angular distribution function (IADF)

• Basic geometric modification – Domain definition

– Truncation

– Mask handling

– Limited shape generation

– Material removal

• Interfacing – Sentaurus Topography 3D – Sentaurus lithography

– Sentaurus Process – Sentaurus Topography 3D

Capabilities

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Intermediate Surface Plots

Watch relevant data on the surface

during etching or deposition

Final shape Intermediate data plots

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Sentaurus Topography

• Using the Rate Formulation Method (RFM) allows the direct formulation of

etch equations.

• In this example: Etching of Silicon with Chlorine radical species (Fr) flux

and ion fluxes (Fi) , scaling factor Ke, sticking coefficient Sr and the etching

yield Y. The incident ion angle distribution (IAD) is defined by the user.

RFM: Ion-assisted Etch(IE) Equation

# Etch rate calculation

Rate formula easily

translated with a Tcl-like

syntax into a command file.

Fluxes are given by RFM

module, yields and constants

are defined by the user.

𝐸𝑅 = 𝑘𝑒 𝑌 ∙ Γ𝑖𝑜𝑛

1 +𝑌 ∙ Γ𝑖𝑜𝑛𝑆𝑠 ∙ Γ𝑟

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Topography to Process Coupling Stress effects during deposition

von Mises Stress

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Lithography ↔ Topography Value links between TCAD Sentaurus simulation tools

Litho (Mask 1)

• Sentaurus Lithography for simulation of 2D

and 3D resist profiles, incl. LER

• Sentaurus Topography 2D with chemical

reaction modeling and reactive ion etching

models

• Sentaurus Topography 3D with empirical

models (resolution and size limited)

Etch (hardmask)

Litho (Mask 2)

Etch (poly)

Resist after post-exposure bake

and development (incl. LER)

After etch

Applications

• Double patterning techniques –

process development

• Vertical integration (e.g. FinFET)

• Study impact of process effects and

correction techniques • LER

• Proximity effects

• Corner rounding with spacers

• Process variability

• Links to device simulation Spacer patterning

for FinFET gate

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Physical Topography Model Calibration

Measurement Plasma Simulation Feature Calibration

Etch Profiles

Operating parameters

•Flow rates

•Pressure

•Frequency

•Temperature

•Bias

In Chamber Metrology

•Current densities

•Ion flux and ratio

•Concentrations

Etch Profile Measurement

•SEM cross section

•Etch rates

•Etch yield

Energy weighted

Ion angle

Distribution (EIAD)

Etch recipe &

Reactor-

geometry

Surface

reaction model

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Outline

Sentaurus Topography 3D introduction

SPTOPO3D project setup

Input file for the built in Ionmill model

Input file for the RFM sputtering model

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Sentaurus Topography 3D

• Sentaurus Topography integrated into Sentaurus Workbench (SWB)

• This allows easy parameterization, interfacing and integration of the

topography simulator with other tools

3D SWB Example

SWB

SPTOPO3D

Parameters

and associated

values

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Sentaurus Topography 3D 3D SWB Example

Right click the Sentaurus Topography 3D icon

Double click “commands…”

strings in format @string@ are

SWB parameters.

Input file: 1. In case of RFM:

1. Model definition with RFM

including e.g. ion reflection

switched on

2. Definition of yields and constants

values, reflection probabilities,

etc.

2. Etch machine definition

3. Etching using defined etch machine

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Outline

Sentaurus Topography 3D introduction

SPTOPO3D project setup

Input file for the built in Ionmill model

Input file for the RFM sputtering model

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• Ions sputter material, no IAED information used

• The sputter rate depends on the impact angle and is

given by an yield function:

Ion Mill: Sputtering

imimimim sss 4

4

2

21 coscoscos)(

0

0.5

1

1.5

2

2.5

3

0 10 20 30 40 50 60 70 80 90

Yie

ld f

un

ctio

n (

arb

itra

ry u

nit

s)

nj

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Built-in Ionmill Model Example Simulation Results

Oxide

Silicon

Resist

Oxide

Silicon

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Outline

Sentaurus Topography 3D introduction

SPTOPO3D project setup

Input file for the built in Ionmill model

Input file for the RFM sputtering model

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Feature-Scale Topography Simulation

Reactor Scale

Wafer

Plasma

Inputs:

•Flow rates

•Pressure

•Temperature

•Frequency

Inputs:

Angular distibution and energy distribution

of ions and neutral particles (IADF, IEDF)

Feature-Scale

IAD and IED interface decouples

feature scale from reactor scale

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Sentaurus Topography 3D

• Neutrals: Energy-independent fluxes with an isotropic

angular distribution

• Ions: Energy-dependent and energy-independent fluxes

with an anisotropic angular distribution

– Ion angular distributions (IAD)

– Yield function

– Reflection probability

Flux Handling

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RFM Sputtering etching Model Example Ion Angular Distribution Input Example

40 mTorr, 1 kW ICP, 0.3 kW

Magnetron, -25 V dc bias, 100 V rf on

coils with -90 V induced dc bias

Integration of

angular distributions

over energies

Ion Flux

normalization

Sentaurus

Topography 3D

Quantemol-D

Plasma Simulation

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RFM Flux Definition

... add_ion_flux model=my_model \ name=I reflection=true \ sputtering=true \ sputter_deposition=false \ energy=independent

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RFM Sputtering etching Model Example Input File and settings

• Sourcing the model

definition, Yield table and

the IAD table

• Defining the model in use

and its associated

parameters

• Setting the initial structure

• Activating the etching

model

Model definition

User-defined Normalized

sputtering yield table

User-defined IAD

Sputtering rate

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RFM Results

Oxide

Silicon

Resist

Oxide

Silicon

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