Most Expected Presenter Final Report Of Wafer Cleaning Seminar 2007

The Final Report of Wafer Cleaning Seminar 2007The Final Report of Wafer Cleaning Seminar 2007

Time: August 9, 2007 (Thursday)

Venue: River Front Business Hotel

Address:3000 Long Dong Ave. Zhang Jiang, Shanghai, China

Sponsor

Tea-Break Sponsor

Special Speaker

Mainly came from SMIC (SH), GMSC, HHNEC, BCD, ASMC, HEJIAN and Shanghai Beiling, 165

qualified fabs’ engineers of totaled 194 participants joined in the 4th Wafer Cleaning Seminar on

August 9th 2007 in Shanghai--the center of China semiconductor manufacturing industry. As the

result of 139 received questionnaires, we work out their preference and favorites on wafer cleaning

technologies as well as speeches at this seminar.

ACER

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Who is most expected to present in next year’s Wafer Cleaning Seminar?

5.33%

2.67% 2.67%

5.33%

1.33%

8.00%6.67%

5.33%

1.33%

16.00%

4.00%

1.33%

9.33%8.00%

1.33% 1.33%

4.00% 4.00%

1.33%

8.00%

4.00% 4.00%

0.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%

14.00%

16.00%

18.00%

Entegris

AMAT

AP&S Internati

onal Gmbh

Applied m

aterials

Charter ECI

CRESTDNS

EKC FSISSECVETEQGSMCHHNEC

INTELJ.T.BAKERSEMITOOL

SEZIM

ECSMICTSMC

Equipment/ Materia

l

ACER

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Copyright © 2007 | FSI International | All Rights Reserved

always thinking // better ®

ZETA® Spray Cleaning System

Extendable, Multi-use Batch Spray Platform

Used By 4 of 5 largest IC Manufacturers

• All-wet PR strip, • Post Ash Cleans• Co, Ni, NiPt Salicide

Shanghai - Aug 9, 2007



ZETA® System Installation Base

• FSI is market leader in batch spray processing

• Over 1000 FSI Spray Systems in fabs worldwide

• ZETA® system is the 6th generation spray processor

BEOL, 31%

Other, 7%

Salicide, 12%

FEOL, 51%

Asia, 40%

Europe, 20%

Japan, 12%

US, 28%

105 ZETA® Systems - Worldwide



ZETA® Chemical Delivery

Variable flow mixing manifold1. Flexibility of chemistries and

application2. Recipe optimize (flow, concentration,

temp.)3. Precise, reliable flow/ concentration4. Sequence flexibility

500:1 ~ 5000:1 H2SO4:HF

1:4 ~ 1:8 H2O2:H2SO4

26:1 ~ 2666:1 H2O:HCl

3.2:1 ~ 320:1 H2O:H2O2

3.2:1:1 ~ 2666:8:1 SC2

5:1:1~ 300:1:1SC1

10:1~ 1000:1dHF

Chemical Blending Capability

8 flowcontrol valves.Flow ranges from 3cc – 5000cc/min



Thermodynamic Considerations

NY1.44H2SO5

YY-----O• (only exist in asher)

N

N

N

Y

Y

Reactive with Carbonized Resist

(aliphatic)

N

N

Y

Y

Y

Reactive with Bulk Resist (aromatic)

1.23O2

1.78H2O2

2.08O3

2.60HSO4•

2.80OH•

Electro-Chemical Potential (eV)

Species

CH2

OH-C-C-

H2SO5 is more effective than H2O2 because sulfuric acid can both dehydrate and dissolve short chain polymer fragments

Need radicals to attack highly cross-linked resist



SPM Piranha Chemistry

• “Caro’s Acid,” if formedH2SO4 + H2O2 � H2SO5 + H2O

H2SO4 + H2O2 � H2SO5 + H2O � HSO4• + OH－

• “Radicals”, are formed in solutionH2SO5 � HSO4● + OH●

• SPM � H2SO4 + H2O2 + H2O



Why Higher Temperature is a Key Factor

Higher on-wafer chemical temperature will lead to more radical formation and higher reactivity towards the amorphous carbon layer

0

100

200

300

400

500

100 120 140 160 180 200 220

temperature (°C)

reaction rate (arb. units)

Standardwet stripprocesses

New wet stripprocess

(assumes 205 kJ/mol activation energy for radical formation)



ViPR™ Spray Strip ProcessWafer Temperature of ~200 °C

Temperature indicating labels protected by 0.7 mm glass wafer with high temperature epoxy.(>204 °C on-wafer indicated)

Catalyst



Keys To Increasing Reactivity

• Higher Sulfuric Acid (Caro’s Acid) Concentration

– higher mixing ratio (>4:1) is desired – least water dilution, but must maintain H2O2 concentration

• Higher Temperature to create more radicals

– Pre-heat sulfuric acid to achieve higher POU mixing temperature (do not pre-heat H2O2 to avoid premature H2O2 degradation)

• Increased Reactivity

– Addition of catalysts significantly increase reactivity



Comparison: ZETA® System vs. Wet Bench55keV, 1E15 As Implant

ZETA® System ViPR™ Process 13.5 min

Immersion 170°C for 30 min

• Residue remains

• Process is not feasible in a wet bench

• All PR removed

• Direct comparison shows ViPR™ process is more effective

Blank coated wafer

Patterned wafer



Cycle Time Reduction:• 105 min (ash+standard wet bench) – 25 min (ViPR™ Process) = 80 min (savings)• 80 min/(1.2 days x 24 hrs/day x 60 min/hr)

~5 % reductionin mask layermanufacturingcycle time



• All-wet strip is a trend driven by technology which also provides productivity benefits

• FSI has a production-proven process for all-wet strip

• Benefits:– Reduce resist removal cycle time from 1.5–3hrs to 0.5hrs.

– Improve overall fab cycle time per mask layer by 3 to 5%

– Eliminate asher induced damage

– Reduce overall material consumption up to 50%

– Lower capital investment by 15 to 33%

ViPR™ Process Summary



Production Performance

0

1

2

3

4

5 5 6 6 7 7 7 8 8 8

tool number

therm

al o

xide lo

ss (Å)

-60

-40

-20

0

20

40

60

5 5 5 6 6 6 7 7 7 8 8 8

tool number

particle delta >65nm

4 ZETA® Systems in Logic Production running ViPR™ Processes

tool #5: ViPR-95 process (5-6 min.) + APM (2min, 70 °C, 1:4:20 )tools #6-8: ViPR-120 process (5 min.) + APM (2min, 70 °C, 1:4:20)

** FSI BKM APM step will remove 1.5Å less thermal oxide

customer targeted oxide loss = 2.5Å



ViPR 95

Delta (>65nm)

-60

-40

-20

0

20

40

60

May20

May21

May23

May24

May26

Jun3

Jun3

Jun5

June

Jul18

Jul31

Aug23

HS02 HS03 HS04 HS05

Delta

Delta (>65nm)

-60

-40

-20

0

20

40

60

May20

May21

May23

May24

May26

Jun3

Jun3

Jun5

June

Jul18

Jul31

Aug23

HS02 HS03 HS04 HS05

Delta

SPC monitor data from production installation

ViPR™ Process Particle Performance



ZETA® System Flexibility

ZETA® System

For Silicide Applications



Contact Technology Evolution

As IC design rules shrink:

� Junction depth decreases, allowable silicon consumption decreases, resistivity becomes a problem

� Silicide evolution: WSiX�TiSi2 �CoSi2 � Ni(Pt)Si- Co gives lower resistivity than Ti- Ni consumes less Si than Co

STIn+ n+

n+ poly

p+ p+

p+ poly

gate

oxide

Co/CoSi2or Ni/NiSi

spacerTiN cap

p-doping n-doping

TiN/TiSi2

Oxide spacer

TiN Fox

(0.8µm ~ 0.5µm ~ 0.25µm ~ 65µm)



1,04E+12

2,80E+11

1,95E+10

1,0E+10

1,0E+11

1,0E+12

1,0E+13

Zeta Std Zeta ACP2 Zeta ACP1

Cobalt residue on Si3N4 (at/cm^2)

Co Reduction on SiN

Note: CoSi2Sheet Resistance was not increased at all.

Typical

range

for WB

POR

ZETA®

System

ACP



• Ti / Ni / NiSi � SPM(5 min) – (APM, 3 min)

• Ti / Ni(Pt) / Ni(Pt)Si � SPM – HPM – SPM – APM

SPM = H2SO4/H2O2 = “piranha;”APM = NH4OH/H2O2/H2O = “SC1”HPM = HCl/H2O2

BKM Chemical SequencesMetal Strip for Salicide Formation

Removes TiN cap and unreacted Ni

Removes unreacted Pt

(patent pending)

Best particleperformance

No Pt Residues• Ni(Pt) > 1000Å/min

• Silicon Oxide < 2Å/min

• Silicon Nitride < 2Å/min

• Poly Silicon < 1Å/min



PlatNiStrip™ Process for NiPt film

Typical nickel strip process will leave Pt residue

PlatNiStrip™ process in ZETA®

eliminates Pt stringer residue

PlatNiStrip™



Cross Contamination Analysis(Ti-coated wafers)

average values: 3 wafers per condition, 5 measurements per wafer (n.d.=0 for calc. of average)

TXRF (Technos) - x1010 atoms-cm-2 (detection limit ~0.1 depending on species)(no entry = not detected)

K Ca Ti Cr Mn Fe Co Ni Cu Zn

1st run Pre 0.02 0.01 0.03

Post 0.01 0.04 0.01 0.02 0.01

2nd run Pre 0.02 0.01 0.04

Post 0.02 0.05 0.01 0.01 0.02 0.01

3rd run Pre 0.05 0.02 0.02 0.1

Post 0.03 0.02

4th run Pre 0.11 0.08 0.01 0.02 0.07 0.02

Post 0.07 0.01

1st run: 3 monitoring wafers + 22 Ti (1000A)

2nd, 3rd, 4th run: 3monitoring wafers + 22 dummy Si



Multiple process flexibility for IC fabrication• FEOL

– All-Wet Photoresist Strip (ViPR™)– Metal Strip for Salicide Formation (PlatNiStrip™ )

– Contact Clean

• BEOL– Cu/low-k Post-Ash Clean– Al/Cu Post Ash Clean (DSP)

• Back End Process• Wafer Bumping

– Photoresist Strip – Flux / Oxide Removal

• General – Wafer Reclaim

x8 ChemicalIn one tool

Fresh chemicalBy POU mixing

Closed Chamber



Summary

• ZETA® system's ViPR™ technology for all wet photoresist removal has been proven in a manufacturing environment.

• ZETA® system is also the most cost effective and lowest contamination salicide wet processing tool (metal strip & contact clean)

• The ZETA® system has been shown to be capable of many FEOL and BEOL of line processes.

• Superior performance is enabled by the use of single pass chemistry in the batch spray tool

• CoO is low due to efficient use of chemicals and high throughput

Most Expected Presenter Final Report Of Wafer Cleaning Seminar 2007

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