most expected presenter final report of wafer cleaning seminar 2007
DESCRIPTION
A presentation for innovated process solution at 2007 China Clean Semnar, voted by audience as most expected present in next year conference.TRANSCRIPT
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.
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
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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
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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
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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
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always thinking // better ®
Copyright © 2007 | FSI International | All Rights Reserved
always thinking // better ®
Copyright © 2007 | FSI International | All Rights Reserved
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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
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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
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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)
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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
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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
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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
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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
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• 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
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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
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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
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ZETA® System Flexibility
ZETA® System
For Silicide Applications
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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)
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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
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• 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
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PlatNiStrip™ Process for NiPt film
Typical nickel strip process will leave Pt residue
PlatNiStrip™ process in ZETA®
eliminates Pt stringer residue
PlatNiStrip™
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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
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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
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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