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3D Stacking: EDA Challenges &

Opportunities

SEMATECH Symposium

Tokyo, Japan

September 2009

Rajiv Maheshwary

Senior Director

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Why 3D IC Design?

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Packaging Technology EvolutionAll these technologies will co-exist

Lo

wM

ed

ium

Hig

h

Low Medium High

Functionality

Den

sity

1990’s

2000’s

2010’s

*Source: Yole Development, 2008

Vertical stack Lateral stack

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3D IC Market Drivers & OpportunityDesign ChallengeDriving Issue Case for 3D (TSV)

Performance/power(Memory Bandwidth

for Multi-media) 1 1.2 1.5

3.9 4.2

9.3 9.7

0

2

4

6

8

10

12Memory Bandwidth Requirement

Dual Core

Quad Core

+ I/O density 100X 2D

*Source: IBS, Major IDM, 2008

More IP Reuse(Time to market, cost)

Mixed Technology(Heterogeneous

Integration) 45-nm130-nm

Miniaturization(Form factor, cost)

More Moore(2.5X higher costs

per process node)

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3D IC TSV Applications

Source: Micron Technology

2008: CMOS Image Sensors

2010: High-density Flash, DRAM

2011-2: Logic + memory

2014: Multi-level 3D SiP’sSource: International Solid-State

Circuits Conference, February 2009

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Requirements for

Market Success

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9

Slide Intentionally

Left Blank For

Handout Purposes

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Test

Requirements for 3D (TSV) IC Market Success

TSV process& Wafer Thinning

Yield

Die Stacking

& Packaging

Design & Methodology

3D ICElements

3D Definition

Eco-System & Standards

Cost

Efficiency

Test

Automation

IDM/

Foundry

OSAT* EDA

EDA

*Outsourced Semi Assembly & Test

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Generic EDA Solution To Enable 3D IC Design

Die 2: Digital

Die 1: Digital Die RF

Passive (Active) Interposer

Package

Multi die planner

Abstraction/Dynamic

Link

Abstraction/Dynamic

LinkIC-Package Interface

Digital RF/AMS Package

Electrical

Analysis

Thermal

Analysis

Netlist

manager

Source: STM, DAC 2009

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Enabling 3D (TSV)

IC Design with EDA

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DRC/LVS

Model(.lib)

Parasitic

Extraction

DR

C/L

VS

Deck

Inte

rco

nn

ect

Mo

de

ling

TS

V

Mo

de

ling

• TSV stress/

reliability analysis

• Special rules TSV

• Interconnect

technology data

Foundry(Tech Files)

3D (TSV) IC Design Flow Vision

Die (Stack)

Partitioning

Synthesis &

DFT

Physical

Design

Extraction

•System level

design exploration

• Logic partitioning

• TSV connectivity

checking w/JTAG

• Test methods

• Multi-die bump &

TSV floorplan

• Auto TSV P&R

• IC-Package I/F

• TSV aware timing,

IR-Drop, EM

analysis

• Thermal analysis

• TSV aware

physical

verification

EDA Design Methodology

Tim

ing

/Po

we

r A

na

lysis

• Extract TSV,

u-bump, backside

RDL metal

Physical

Verification

Stack

Sign-off

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TSV Induced Stress and Reliability

Through Silicon Via

Interconnects

Transistors

Bumps to connect

to the package

Interconnects

Die 1

Die 2

(thin)TSV

m-bump

Typical Back-to-Front TSV Stack

Die 1

Die 2

(thin) TSV

Transistor is

being squeezed

or stretched

by adjacent TSVs

m-bump

The amount of proximity

effects depend on

geometry shape,

location, and orientation

Material deformation

leads to mobility change

Stress affects transistor

performance

Die 1

TSVTSV squeezes

or stretches

adjacent

interconnects

Die 2

(thin)

m-bump

Stress affects BEoL

reliability

De-bonding and

De-lamination

could occur under

additional stress

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3D IC Stress/Reliability Analysis Solution

Die Thinning

t=400um

t=200um

t=100um

t=20um

Compressive film stress

Von Mises Effective Stress (MPa)

TSV

001 Wafer, 110 Orientation

Effective Stress

Submodel 1

Submodel 2

Submodel 3

Global Model Multi-scale Modeling Reliability Analysis

Performance VariationStress HotspotsWafer Warpage

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3D IC Test Strategies

• Challenge– Stack testing (efficiency &

low cost)

– Low pin count test

• Solution– Test one die at a time with

isolation logic (core or boundary)

– 1000X test compression at very low pin cost

– Inter-die testing methodology

– Use/extend IEEE 1149.1 and 1500 test standards

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Today’s Flip Chip Flow

3D IC Physical Design Challenges

Chip connections

“re-distributed”

from pads to

bumps

Re-Distribution

Layer (RDL)

routing is on

upper-most layer

Bumps (solder balls)

are placed overlaying

the complete chip

Bump

cell

RDL

route

IO

pad

Substrate

Package

Chip

Bump3D IC

• Represent TSV & backside

metal in technology file

• Automatic P&R

• Support multiple chips

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TSV, IO and Bump Placement & Routing

TSV’s

Bumps/Lands

TSV’s connected

to I/O

Placement

Blockages

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3D IC Extraction Challenges

Substrate

Package

Chip

Bump

• Single-sided substrate

• Includes extraction of routing

& RDL layers

• Parasitic netlist represents a

single die

Today 3D IC

• Parasitic effects of TSV, u-bump,

bonding layer, interposer routing

• Support of multiple chips

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3D IC Extraction Solution: Stacked Die

• “2D” extraction for Chip 1

• “3D” extraction for Chip 2 with TSV and backside routing

• Generate single spice netlist with parasitics for top, TSV and

back metal layers

Chip 2

Chip 1

Interconnect Technology File

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3D IC Thermal Considerations

• Challenge– Multiple heat sources (stack)

– Substrate thinning yields poor heat dissipation per die (2D)

– Elevated thermal gradient in 3D

• Implications– Reliability

– Timing

Peak temperature

is 15% higher

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3D IC Thermal Solutions

• Accurate thermal

modeling & analysis

• Thermal-aware

physical design– 5% increase in wire-length

@ 2D peak temperature

• Thermal TSV’s

1

2

3

4

5

Heat sources

(distributed)

White space

used for

Thermal Vias

Thermally Optimized Floor-plan

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• 3D IC Market Drivers

– Cost, Performance/Power

– Heterogeneous integration

• Customers expected to have

production devices starting 2011

– Logic + DRAM and Logic + Logic

– $20B* TSV devices by 2013

• Synopsys Focus

– Enable design flow with partners

– Lead definition of emerging

interoperability standards

Summary

Source: Gartner Semiconductor Industry Briefing, June 2009

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