psm: phase shifted stevebrainerd1/photolithography/week 9 a · 9/11/2004 psm brainerd 1 psm: phase

9/11/2004 PSM Brainerd 1

PSM: Phase Shifted Masks Physics Performance to date Types: Embedded Attenuated (leaky chrome) (Att-PSM): :

EAPSM Alternating aperture (Alt-PSM): AAPSM and SCAAM Unattenuated ( Chromeless): UAPSM Rim Shifters Multi-phase Low k1 PSM processes; Double exposure techniques:

IDEAL, GRATEFUL

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PSM: Phase Shifted Maskshttp://www.kla-

tencor.com/company_info/magazine/autumn00/AutumnMag00.pdf

RET Reticle enhancement techniques by Node Embedded Attenuated (leaky chrome) (Att-PSM): : EAPSM Alternating aperture (Alt-PSM): AAPSM

9/11/2004 PSM Brainerd 3

Phase Shifted Masks: PSMhttp://www.gbhap.com/Science_Spectra/20-2-article.htm

Phase Shifted Mask IDEA 180o phase shift between spaces on mask grating ( Alt-PSM)

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PSM: RET techniques

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PSM: Phase Shifted Mask Basics: Physics

OPD: to create 180o phase shift at edges

Phase shift is given by: = 2t (n-1) /

n = refractive index of shifter material

= wavelength of exposure radiation

t = thickness of shifter material

180o Phase shift is given by: = = 2t (n-1) /

then shifter thickness (depth): T ()= /[2* (n-1)]

So one can tune a given material with refractive index n to be a PSM at a specific wavelength by adjusting the thickness.

9/11/2004 PSM Brainerd 6

PSM: Phase Shifted Mask Basics: UnattenuatedChromeless

180o Phase shift is given by: = = 2t(n-1)/ then shifter thickness (depth ): T ()= /[2* (n-1)]

9/11/2004 PSM Brainerd 7

PSM: Alternating Aperture Levenson idea (IBM):

9/11/2004 PSM Brainerd 8

PSM: Alternating Aperture Binary mask electric field and intensity: I = E2

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PSM: Alternating Aperture Phase shifted mask electric field and intensity

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Alt-PSM: Alternating Aperture

AAPSM fabrication process

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PSM: Alternating Aperturehttp://www.advlitho.com/content/Papers/4346-72.pdf

AAPSM Issue: IntensityIntensity difference between apertures

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PSM: Alternating Aperturehttp://www.advlitho.com/content/Papers/4346-72.pdf

AAPSM Issue: Focus issue

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PSM: Alternating Aperturehttp://www.advlitho.com/content/Papers/4346-72.pdf

AAPSM : correction for focus and intensity issue

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PSM: Alternating Aperturehttp://www.advlitho.com/content/Papers/4346-72.pdf

AAPSM Issue: Focus and intensity mismatch

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PSM: Alternating Aperture AAPSM improved CD control = Aerial image intensity by

undercutting

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PSM: AAPSM Alternating Aperturehttp://www.numeritech.com/download/files/53/ntiprsn.pdf

Alternating Aperture PSM ( hard Phase shifting): Quartz etch fabrication

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PSM: AAPSM Alternating Aperture: undercut issuehttp://www.numeritech.com/download/files/53/ntiprsn.pdf

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PSM: SCAAM Process http://www.ultratech.com/about/presentations/T.Ebihara.PDF

9/11/2004 PSM Brainerd 19

PSM: SCAAM Process http://www.ultratech.com/about/presentations/T.Ebihara.PDF

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PSM: SCAAM Process http://www.ultratech.com/about/presentations/T.Ebihara.PDF

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Att- PSM: EAPSM Embedded Attenuated Phase shift:http://www.advlitho.com/content/Papers/4000-126.pdf

Attenuated Phase shift: also called leaky chrome, weak shifter, and EAPSM( Embedded Attenuated Phase Shifted Mask): Typically MoSi2with a 6-8% transmission at a thickness that causes a 180o phase shift. Most manufacturable Phase shift mask process! Very common for contact layer!

Leaks or transmits 6% 180o phase light = weak shift at edge!

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PSM: EAPSM Embedded Attenuated Phase shift:

Attenuated Phase shift: weak shifter, and EAPSM :MoSi2 most common

Interfernce causes cancelation= higher contrast!

Leaks or transmits 6% of 180o phase light

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PSM: EAPSM Embedded Attenuated Phase shift:Unwanted constructive interference

EAPSM : Printing unwanted features>> Side lobe issue Unwanted constructive interference!

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Att-PSM: EAPSM Embedded Attenuated Phase shift:http://www.ultratech.com/about/presentations/Y.Morikawa.pdf

EAPSM Future materials for Phase shift and partial transmission: Need to consider the non-zero extinction coefficient (k) slight phase impact and reflectivity!

9/11/2004 PSM Brainerd 25

PSM: Double Exposure Process

IDEAL: (Canon): Innovative Double Exposure by Advanced Lithography >. 100- 130nm gates!!

Uses 2 reticles: 1. PSM Levenson ( master can re-use) 2. Binary (custom trim) Exposure 1 using AAPSM with sub- threshold dose Exposure 2 using BIN is sub-threshold, but dose is

additive in areas of overlapping exposure(double) creating a resist pattern.

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PSM: Double Exposure Process: Low k1 processingCanon Process Development

Dose distributions: Resist threshold 2 or greater

If Dose => 2.0 thenphotoresist reacts!!

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PSM: Double Exposure Process: Low k1 processingCanon Process

IDEAL for logic gates

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PSM: Double Exposure Process: Low k1 processing

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PSM: Double Exposure Process: Low k1 processing Aerial Image simulations of Canons IDEAL T = Resist Threshold

Positive Photoresist (lines) Negative Photoresist (lines)

No exposure

Exposure ( no photoresist)

1st dose

2nd dose

Addition 1 + 2

Exposure

No exposure ( no photoresist

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PSM: Double Exposure Process: Low k1 processing

http://www.usa.canon.com/indtech/semicondeq/news_ideal.html Aerial Image simulations of IDEAL

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PSM: GRATEFUL Process Low k1 processinghttp://www.fsi-intl.com/products/ware.pdf

This just shows the trim exposures!

This would be the actual pattern.

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PSM: GRATEFUL Process Low k1 processinghttp://www.fsi-intl.com/products/ware.pdf

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PSM: GRATEFUL Process Low k1 processinghttp://www.numeritech.com/download/files/42/gratefulcomplete.pdf

Creation of PSM contacts with double exposure using negative photoresist.

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PSM: GRATEFUL Process Low k1 processinghttp://www.numeritech.com/download/files/42/gratefulcomplete.pdf

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PSM: GRATEFUL Process Low k1 processing100nm Node Lithography with KrF?? Paper:

M.Fritze etal. MIT

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PSM: GRATEFUL Process Low k1 processing100nm Node Lithography with KrF?? Paper:

M.Fritze etal. MIT

9/11/2004 PSM Brainerd 37

PSM: GRATEFUL Process Low k1 processing100nm Node Lithography with KrF?? Paper:

M.Fritze etal. MIT

PSM: Phase Shifted MasksPSM: Phase Shifted Maskshttp://www.kla-tencor.com/company_info/magazine/autumn00/AutumnMag00.pdfPhase Shifted Masks: PSMhttp://www.gbhap.com/Science_Spectra/20-2-article.htmPSM:PSM: Phase Shifted Mask Basics: PhysicsPSM: Phase Shifted Mask Basics: UnattenuatedChromelessPSM: Alternating AperturePSM: Alternating AperturePSM: Alternating ApertureAlt-PSM: Alternating AperturePSM: Alternating Aperturehttp://www.advlitho.com/content/Papers/4346-72.pdfPSM: Alternating Aperturehttp://www.advlitho.com/content/Papers/4346-72.pdfPSM: Alternating Aperturehttp://www.advlitho.com/content/Papers/4346-72.pdfPSM: Alternating Aperturehttp://www.advlitho.com/content/Papers/4346-72.pdfPSM: Alternating AperturePSM: AAPSM Alternating Aperturehttp://www.numeritech.com/download/files/53/ntiprsn.pdfPSM: AAPSM Alternating Aperture: undercut issuehttp://www.numeritech.com/download/files/53/ntiprsn.pdfPSM: SCAAM Process http://www.ultratech.com/about/presentations/T.Ebihara.PDFPSM: SCAAM Process http://www.ultratech.com/about/presentations/T.Ebihara.PDFPSM: SCAAM Process http://www.ultratech.com/about/presentations/T.Ebihara.PDFAtt- PSM: EAPSM Embedded Attenuated Phase shift:http://www.advlitho.com/content/Papers/4000-126.pdfPSM: EAPSM Embedded Attenuated Phase shift:PSM: EAPSM Embedded Attenuated Phase shift:Unwanted constructive interferenceAtt-PSM: EAPSM Embedded Attenuated Phase shift:http://www.ultratech.com/about/presentations/Y.Morikawa.pdfPSM: Double Exposure ProcessPSM: Double Exposure Process: Low k1 processingCanon Process DevelopmentPSM: Double Exposure Process: Low k1 processing Canon ProcessPSM: Double Exposure Process: Low k1 processingPSM: Double Exposure Process: Low k1 processingPSM: Double Exposure Process: Low k1 processing http://www.usa.canon.com/indtech/semicondeq/news_ideal.htmlPSM: GRATEFUL Process Low k1 processing http://www.fsi-intl.com/products/ware.pdfPSM: GRATEFUL Process Low k1 processing http://www.fsi-intl.com/products/ware.pdfPSM: GRATEFUL Process Low k1 processing http://www.numerit