cost efficient organic inline cleaning sen...- common process is a kind of sc1 – psc1 (koh + h2o2)...
TRANSCRIPT
ConfidentialPLEASE NOTE THE DISCLAIMER ON THE LAST PAGE
Cost Efficient Organic Inline Cleaning for all Si-Wafer Sawing Processes
2015-06-19
Freiberger Silizium Tage Ilker Sen
Confidential 2015-06-19 2
Content
1. We are Schmid
2. Motivation
3. Comparison sawing process
4. New Schmid cleaning process
5. Results
6. Conclusion
Confidential
1. We are SCHMID
2015-06-19 3
� Owner-operated family business in its 5th generation (1864)
� Over 1,400 employees worldwide
� Sales, production and service in 23 locations worldwide
� 8 production facilities worldwide with over 80,000 m²
� 5 technology centers in all key markets
� DIN EN ISO 9001 certified
� SAP ERP fully integrated
ConfidentialS
OL
UT
ION
S
1. We are Schmid
2015-06-19 4
Photovoltaics
PCB
Display and Optics
Industrial Solutions
Energy Systems M
ark
et/
Cu
sto
mer
Req
uir
em
en
ts
Tool Platforms� Wet Process� Vacuum Technology� High Temperature Process� Printing� Laser Treatment� Automation and Intralogistics� Vision and Inspection
Process Technologies
� Coating
� Structuring
� Cleaning & Conditioning
� Modification
� Handling & Controls
R&
D (
SC
HM
ID T
ech
no
log
y C
en
ters
)
Confidential 2015-06-19 5
2. Motivation
- Alkaline texturizing process is very sensitive for organic residues
- Without special surface treatment no homogenous texturizing of diamond wire sliced wafers possible
- “Schmid clean” process is able to avoid all organic slicing influences
- Common process is a kind of SC1 – pSC1 (KOH + H2O2)
- Instead of NH4OH in SC1 is KOH used in pSC1
Confidential 2015-06-19 6
2. Motivation
- “Schmid Clean” process has lower costs than pSC1 process
- “Schmid Clean” process is easier to control than pSC1
- Removing organic residues after all sawing processes
(oil, slurry, water based coolant)
- Preparing wafer surface for alkaline texturizing
Confidential
3. Comparison sawing process
2015-06-19 7
Slurry / Oil process ( PEG / Oil +SiC) Diamond wire + water based coolant
Wire
Slurry
(Loose abrasive)
SiliconSilicon
Diamond layer
(Fixed abrasive)
Core wire
Feed
wire
Used
wire
Slurry
nozzle
Cut
direction
Silicon
brick
Slurry
nozzle
Wire direction
Feed
wire
Used
wire
Coolant
nozzle
Cut
direction
Silicon
brick
Coolant
nozzle
Wire direction
(Pilgrim mode)
Confidential 2015-06-19 8
3. Comparison sawing process
W
a
W
a
W
af
er
fe
r
Steel wire
D
i
a
m
a
n
t
d
r
a
h
t
� PEG / Oil Slurry sawing process� Diamond wire sawing process
� Slicing direction continues � Slincing direction forward andbackward
� Diamond wire
Confidential 2015-06-19 9
4. New Schmid Cleaning process
- Problem:
- Different sawing processes (slurry, oil, waterbased coolant)
- Influence of sawing process to the wafer surface
- Influence of coolant to the wafer surface (Diamond wire process)
- Combination of oxide layer defects and organic residues
- Customers are using different wafer suppliers with different cleaning processes
- Different texture results
SC
HM
ID G
roup
Confiden
tial
10
4. New Schmid cleaning process
2015-06-19
Pic. 1: Wafer after standard
cleaning not optical clean
Pic. 2: Wafer after standard
cleaning optical clean
Both wafers have
problems in alkaline
texturizing:
Optical clean is not
clean enough
SC
HM
ID G
roup
Confiden
tial
2015-06-19 11
4. New Schmid Cleaning process
2. Solution:
- Searching for a process, which is able to replace H2O2
- Searching for a process, which is very robust and stable in
comparison pSC1
Working principle:
Org (C) + Ox → CO2↑ + Red
SC
HM
ID G
roup
Confiden
tial
4. New Schmid Cleaning process
SC
HM
ID G
roup
Confiden
tial
4. New Schmid cleaning process
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
CompetitorInline
SCHMIDreference
New SCHMIDClean
Cle
an
ing
Co
sts
pe
r W
afe
r, in
de
xe
d
Costs Benchmark for Cleaning withOxidation Step
COO Materials / Consumables Costs
2015-06-19 13
SC
HM
ID G
roup
Confiden
tial
5. Results
2015-06-19 14
� No organic and metallic residues
� No visible contamination: oil/grease, finger prints, water stains, slurry stains, coolant stains
� All organic masks are removed
Etch rate per side [µm] Reflection [%](400-1000 nm)
Remarks
6,0-6,5 11,4-11,0 Very uniform surface in
texturizing and better VOC
SC
HM
ID G
roup
Confiden
tial
6. Conclusion
2015-06-19 15
� “Schmid Clean” process is a very robust and stable process
� Replace H2O2 through cheap and common available chemical
� Very low working concentration
� Better etch rate in texturing process and better reflection
� Reduced costs for consumables
� No special waste water treatment necessary
� Inline process
� Low temperature process
SC
HM
ID G
roup
Confiden
tial
www.schmid-group.com
THANK YOU FOR YOUR ATTENTION!
2015-06-19 16