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Dr. Reinhard Voelkel

CEO SUSS MicroOptics SA

September 9 th , 2010

Innovative Mask Aligner Lithographyfor MEMS and Packaging

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SUSS Micro-Optics

SUSS MicroOptics is a leading supplier for high-quality Micro-Optics and part of SUSS MicroTec Group

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SUSS MicroOptics is “Preferred Supplier” for Carl Zeiss SMT AG providing Micro- Optics‟components for Deep UV Illumination in ASML Lithography Systems.

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Micro-Optics in Front-End Lithography

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Diffractive Optical Elements (DOE)MEMS (FlexRay ™)

Customized Illumination

Excimer Laser (193nm)Laser Beam Shaping

Laser Beam Homogenizing

Customized IlluminationPupil Shaping (DOE)

Now: FlexRay ™programmable illumination

technology

MicrolensHomogenizer

Micro-Optics is Key Enabling Technology in

Front-End Lithography

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MEMS: Photolithography

Mask Aligners are the work horse of SEMI industry since the very beginning

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S U S S M i c r o

T e c

M A 2 0 0 C o m p a c

t

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Back End Lithography

Mask Aligners Lithography is „Shadow Printing “Mask illumination using UV light

Resolution <=> proximity gap

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Wafer

Mask

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Photolithography

Mask Aligners are• Mature technology

• Cost-effective• Fast (high throughput)• Service friendly

• Easy to use• Convenient

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S U S S M i c r o

T e c

M A 2 0 0 C o m p a c

t

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Challenge

BUT

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a Mask Aligner isa Mask Aligner isa Mask Aligner!

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Myth or Facts?

Reaching limits: Change to Projection?Think twice, because

– High capital investment – High costs per wafer – Change established processes

– Reduced focus budget – Can„t print to the very edge of wafer...

Mask Aligners are so convenient!

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Mask Aligner Lithography

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Illumination makesthe difference!

• Diffraction• Partial Coherence

Parallel Light Apodization

Parallel Light Diffuse Light

CONTACTGAP: 20 µm

GAP: 50 µm

GAP: 100 µm

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Micro-Optics is also Key EnablingTechnology for Mask Aligners!

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Fly „s Eye HomogenizerMicrolens Optical Integrator (Köhler )

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I(x)

x

I(x)

x

Flat-Top IntensityProfile

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MO EXPOSURE OPTICSInnovative Illumination System for SUSS Mask Aligners

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Technology Backbone:Microlens Optical Integrators (Köhler)

OpticalIntegrator (I)

Fourier Lens ƒFL

Fourier Plane

OpticalIntegrator (II)

Fourier Lens

ƒFL

Fourier Plane

F l a t - t o pi n

t en

s i t y

pr of i l e

Exchangable IIlumination Filter Plate (IFP)

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Patent pending

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MO Exposure Optics

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Microlens Array

Optical System MA 200

Library ofIlluminationFilterPlates (IFP)

Microlens-based Optical Integrators

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Excellent UniformityIndependent of Lamp Position

Deviation from mean value in [%] for Ø200mm in MA200 Compact

Lamp Position: Uncritical

Lamp Tilt: Uncritical16

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Stabilize the Mask Aligner

FeaturesStable Light SourceExcellent Uniformity

Telecentric Illumination

BenefitsReduced Downtime

Improved CD UniformityLarger Process WindowHigher Yield

MO Integrator

MO Integrator

IFP Module

Micro-Optics IlluminationFilter Plate

MO Exposure Optics

Standard Mask Illumination Telecentric Mask Illumination

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Technology Enhancement

Microlens-based MO Exposure Opticsprovides

• Stabilized light source• Excellent light uniformity• Telecentric illumination

in Mask Aligners

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Exchangeable Illumination Filter Plates

Features – HR to LGO change in less than 1 min – Illumination filter plates (IFP) – Customized illumination

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IFP-HR„High Resolution“

IFP-LGO„Large Gap“

IFP-C90„More Light“

Exchangeable Illumination Filter Plate (IFP)

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Optimize DiffractionCustomized Illumination

201.2µm thick resist (AZ 4110), 100µm Proximity Gap, SUSS MA8

Photomask PatternSquare 10x10µm 2

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Optimize DiffractionCustomized Illumination

Features – HR to LGO change in <1 min – Illumination filter plates (IFP) – Customized illumination

Benefits – Flexible illumination – Diffraction reduction – Resolution enhancement

technology (RET) – Optimized lithography process

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HR: High Resolution LGO: Large Gap

Library of Illumination Filter Plates (IFP)

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Optical Proximity Correction (OPC)

Aerial image 6μm lineProximity gap 40μmMask layouts (right)OPC assist features (bottom)Reduction of the rounding ofthe inner and outer corner

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OPC assistfeatures

Maskpattern

Aerial image (simulation)

Ref: Kristian Motzek, FhG-IISB, SUSS Report Sept 2010

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Optical Proximity Correction (OPC)

23Square10µm x 10µm, Proximity Gap 50µm, Photoresist AZ4110, 1.2um thick

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Expertise inLithography Simulation

Lithography SimulationSource-Mask Optimization Service

Research & Technology Partners

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Simulation 3D Resist Structure(Layout Lab, GenISys)

Printed Resist Structure

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Source-Mask Optimization Service

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Example: LEDRequirements for PSS

Patterned Sapphire Substrate – Epitaxy

– Effiency – Beam Confinement

Process – Hexagons/Cones, ≈ 3µm – RIE-ICP (Chlorine) Etching

www.corial.net

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Example: LEDSource-Mask Optimization

Optical Proximity Correction(Proximity Gap 30µm)

MO Talbot Lithography(Proximity Gap 102µm)

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MO Talbot LithographyPeriodic Structures (PSS)

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Pitch 5 µm Resist 2 µm thick Etching RIE (Bosch)

Silicon Proximity Gap 102 µm

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MO Talbot LithographyPeriodic Structures (PSS)

Pitch 5 µm Resist 2 µm thick Etching RIE (Bosch) Silicon Proximity Gap 102 µm

0.8 µm

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MEMSThick Photoresist (SU8)

Very thick photoresist – Improvement of Footing – Sidewall shaping

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Improvement of footing and sidewalls withthick SU8 using MO Exposure Optics

300µm thick SU8Resolution 25µm

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Example: ADP, TSV & 3DOPC Fresnel

Photoresist AZ1518, 5µm thick

11µm via800µm proximity gap

Via shaping

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Side view

Top view

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Example: ADP, TSV & 3DOPC Fresnel

Resulting Aerial Image Depth of focus(DOF)

Illumination FilterPlates (IFP)

DOF

OPC Structure(Fresnel-type)

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11µm via at 800 µm proximity gap

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Example: ADP, TSV & 3DOPC Fresnel

Benefits – Very large proximity gap

– Via shaping possible – Extended Depth of

Focus (DOF) – Very short exposure

time (throughput)

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Gap Ø Via DOF

100 µm 2 µm 5 µm

200 µm 3 µm 15 µm

300 µm 5 µm 30 µm

400 µm 7 µm 60 µm

500 µm 10 µm 100 µm

700 µm 14 µm 200 µm

Typical parameters for via printingusing OPC Fresnel Technology

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Advanced Mask Aligner Lithography

A Mask Aligner is aMask Aligner is a

Mask Aligner!Yes! But...

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Stabilizedlight source

Uniformand

telecentricillumination

Customizedillumination

Improvedprocess stabilityProcess window

enlargementYield

improvement

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Technology Enhancement

MO Exposure Optics enables• Customized Illumination

• Optical Proximity Correction (OPC)• Source-Mask Optimization (SMO)

in SUSS Mask Aligners

Advanced Mask Aligner Lithography

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Summary

Quick wins – Improved CD uniformity

– Higher throughput – Less downtime

New process parameter: Illumination! – Customized illumination – Optical Proximity Correction (OPC)

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SUSS.

Our SolutionsSet Standards

SUSS MicroTecSUSS MicroOptics

www.suss.com