Virtual Fabrication – Changing the Trajectory of Chip Manufacturing

Dinesh R. Bettadapur Vice President, Business Development

dinesh@coventor.com

Presentation Outline

• Problem Statement

• Solution: Virtual Fabrication

• Virtual Fabrication Value Triangle #1

• Use Cases

• Virtual Fabrication Value Triangle #2

• Use Cases

• Summary

2 DB CASPA AC 2016

Logic Complexity is Going Way Up

Gate All-Around

Nanowires

Planar

Transistor

3D

FinFET

Device

Dramatic Increase in Structural Device Complexity

DB CASPA AC 2016 3

Memory Complexity is Skyrocketing!

3D NAND – 36L 3D NAND – 48L 3D NAND – 72L

Memory Structures ≈ High Rise Buildings!

4 DB CASPA AC 2016

Exploding R&D Wafer Budgets

5 DB CASPA AC 2016

Exponential Increase in Development Wafer Runs

Exploding Process Development & Fab Costs

New Process Cost: > $2B & New Fab Cost: > $5B 6 DB CASPA AC 2016

Old Paradigm: Build & Test

Experimental Lots:

Splits, Short-Loops

FEOL/BEOL or Full-Flow

Characterization:

Inline Metrology

Offline Physical Analysis

Electrical Testing

Feedback:

Engineering Analysis

POR Change

Test-Chip Design:

Characterization structures for

known/expected targets and challenges

Repeat Every

~1-3 Months

New Test-Chip:

New & updated targets

Unexpected challenges

Repeat Every

~1 Year

“Cycles of Learning”

7 DB CASPA AC 2016

Old Paradigm Applied to Advanced Process Development

8

More processes to monitor

More test-chip structures!!!

Longer fab cycle time

More wafers required to cover options

More tests and measurements More complex problems to solve

MUST ELIMINATE CYCLES OF LEARNING TO ACCELERATE DEVELOPMENT

DB CASPA AC 2016

Single Exposure vs. Multi-Patterning

9

Litho Steps Etch Steps Deposition

Steps Multi

Patterning 1 9 12 DB CASPA AC 2016

Litho Steps Etch Steps Deposition

Steps Single

Exposure 1 1 1

Solution: Virtual Fabrication

• Virtual Fabrication is a powerful virtualization technology based on advanced 3D process modeling & simulation – • Process visualization (FEOL, MOL, BEOL)

• Integrated process effects at each unit process step

• Process variation impact on device yield

• Benefits – • Significantly reduced wafer costs

• Elimination of multiple cycles of learning

• High speed process-predictive simulation

• Broad set of applications –

• Research Path finding Yield ramp up

DB CASPA AC 2016

Virtual Fabrication Value Triangle #1

Virtual

Fabrication

Vendors

IDMs and

Foundries

Equipment

Companies

Tool Spec, Process Equipment

Unit Process Requirements

Advanced Chip Manufacturing Requires Higher Degree of Collaboration 11 DB CASPA AC 2016

Use Case: Cross Wafer Uniformity Improvement

Unit Process Variations Integrated Process Effects 12 DB CASPA AC 2016

Use Case: Process Variation Reduction

SEMICON West 2014 & IEDM 2015

Virtual Fabrication is used to prioritize and synchronize

inline specifications for variation reduction

13 DB CASPA AC 2016

• Evaluation of new 7nm integration schemes

• Two RMG schemes: PMOS 1st and NMOS 1st

Use Case: 7nm Process Branch Decision

"RMG nMOS 1st Process Enabling 10x Lower Gate Resistivity in N7 Bulk FinFETs", VLSI Symposium 2015

Virtual Fabrication is used to evaluate parallel integration

schemes optimal process decision

• NMOS 1st shows significant advantages

• Clear gap fill benefits and HfO2 not exposed

• No barrier is needed

• Better resistivity (extracted from transmission lines)

14 DB CASPA AC 2016

Use Case: Memory & Logic Defect Prediction Studies

Mandrel Litho Defects

1 = Resist Bubble

2 = Scumming

3 = Scumming

Block Litho Defects

4 = Scumming

5 = Resist Bubble

Completed Mx Module

1,3,5 = No Impact

2 = Single-Break Open

4 = Double-Break Open

Virtual Fabrication is used to model defect evolution and predict future process impact 15 DB CASPA AC 2016

Virtual Fabrication Value Triangle #2

Virtual

Fabrication

Vendors

Foundries

Fabless

Design

Houses

Manufacturable Designs

Design rules, Encrypted process parameters,

Yielding wafers

Win-Win-Win Partnership 16 DB CASPA AC 2016

Use Case: Design-Technology Co-Optimization

Silicon-Accurate

Geometry in 3D

3D Search for Process Failures

M1-V1-M2

BEOL Braid

Design and

Layout in 2D

Iterate virtually through design-manufacturing

cycles

Adjust Design Rules

and Specify Waivers

Min Insulator Failures Net ID and Count Min Line Width

Failures

3D Search for Process Failures

17 DB CASPA AC 2016

Use Case: 3D DTC

Virtual Fabrication Enables 3D Design Technology Checking

Signoff

2D Single-Level Checks:

Litho Printability

Pattern Density

etc.

2D DRC

3D DTC Checks:

Minimum Insulator

Contact Area

etc.

Process &

Variation

Data

3D DTC

18 DB CASPA AC 2016

Use Case: BEOL Process Variability Analysis

• Virtual Fabrication detects contact opens or shorts

Baseline

two electrical contacts (two colors)

Via over etch

results in contact short (one color)

CONTACT 1

Via under etch

results in contact open (multiple colors)

CONTACT 1 CONTACT 2 1 CONTACT 2 3 4 5 6 7 8 9

Metal contact area limitation Metal line width limitation Metal line spacing limitation

*Blue color indicates violation

• Virtual Fabrication detects high resistance interconnect failures*

19 DB CASPA AC 2016

Use Case: Litho Process Variability Prediction

© Coventor, Inc. Confidential

3D resist contours for M1

Full M1 process integration

Dose: -10%

Defocus: -50nm

Dose: +10%

Defocus: +50nm

Net counts identifies

short and open failures

Space checks highlights

proximity failures

Virtual Fabrication Enables Accurate Prediction of Integrated Structural Failures

Materials checks locate

high resistance regions

20 DB CASPA AC 2016

Summary

• Process complexity and process development costs are growing exponentially for sub-20nm chip manufacturing

• Process complexity drivers: Complex device architectures (FinFET, 3D NAND, GAA), Complex patterning schemes (quad patterning), and Complex structures (BEOL passives, Memory)

• Old paradigms of build & test and silo-based unit process development are simply too expensive and time consuming!

• Virtual Fabrication is an innovative and powerful integrated process modeling technology that can enable significantly lower wafer costs and reduced cycles of learning

• Virtual Fabrication enables broad array of use cases in Process R&D and Chip Manufacturing

• Virtual Fabrication has been widely adopted by the world’s leading foundries, memory makers, logic manufacturers, and equipment companies

21 DB CASPA AC 2016