Front-end, Back-end and Substrate Slurries: Key Process...
Transcript of Front-end, Back-end and Substrate Slurries: Key Process...
copyright : Asahi Glass Co.,Ltd.
Your Global Partner in Material Solutions™
Front-end, Back-end and Substrate Slurries:
Key Process Data and Advantages
copyright : Asahi Glass Co.,Ltd.
Current Products
• Ceria Slurry
– STI/RMG process (used for 22nm HVM)
– Poly Si CMP: high rate and selective to oxide and
SiN
– Poly Stop – High TEOS/Poly selectivity
– TSV – Backside: Tunable Cu, TEOS rate
• Cu Slurry
– TSV: Frontside: high Cu rate, Cu/Ta, Ti ratio
– Cu : High planarization on soft pad
• Barrier: Customized for integration
• Sapphire: good Ra, low cost
• SiC: good Ra
copyright : Asahi Glass Co.,Ltd.
Device Integration and Polishing applications
Logic application TSV application
Cu / Barrier CMP APLANADOR series
PMD CMP CES series
STI CMP CES seriesW
Cu
P-well N-well
Substrate
STI
Cu
Cu
Poly-Si
Si
Poly-Si CMP CES series
High Cu rate CMPAPLANADOR series
Cu SiBare-Si CMP CES series
Flash application DRAM applicationCu / Barrier CMP
APLANADOR series
ILD CMP CES series
STI & RMG CMP CES series
Poly-Si CMP CES series
Capa-citor
Cu
W
Substrate
Cu
W
STI
Substrate
Poly-Si
STI
copyright : Asahi Glass Co.,Ltd.Page 4
CES-330F New
defe
ct c
ount
The CES-350 abrasive show 1/3 of the defectivity for CES-330 abrasive.
Comparison of defect count as a function of ceria particle size
CES-350F
copyright : Asahi Glass Co.,Ltd.
Step Height Reduction and Overfill Removal:
• CES-333-2.5 demonstrated auto-stop properties.
• Thick overfill cleared by dilute slurry polishing.
• High selectivity to SiN
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Polishing time (sec)
Act
ive
HD
P T
hic
kn
ess
(A)
500um L/S50um L/S30% dens70% dens.
Auto stop Diluted slurry
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5500
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Polishing time (sec)
Fie
ld H
DP
Thi
ckne
ss (
A)
500um L/S50um L/S30% dens.70% dens.
Auto stop Diluted slurry
CES 333F series type slurry for STI and RMG
copyright : Asahi Glass Co.,Ltd.Page 6Page 6
pressure
Removal
rate
pressure
Removal
rate
Auto stop polishing
Polishing pressure
Low dishing polishing
Polishing pressure
Threshold > polishing pressure Threshold < polishing pressure
Additive chemistry engineering for improved planarization: Concept of higher planarity polishing slurry
Higher planarity -smaller dishing (range)-smaller SiN loss (range)
Removal rate would be lower,
when step height cleared.
Removal rate would be lower,
when dishing occurred.
copyright : Asahi Glass Co.,Ltd.Page 7
pressure
Rem
ova
l
rate
Polishing pressure
CES-333
CES-336
New additives protect trench oxide at low down force area.
Removal rate ratio(High/low pressure) is higher with new additive.
Concept of new additive for higher planarity
In case of Oxide clearing polish
copyright : Asahi Glass Co.,Ltd.
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tre
nch
oxi
de
th
ickn
ess
[A]
polish time[s]
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tre
nch
oxi
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ickn
ess
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polish time[s]
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tre
nch
oxi
de
th
ick
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ss[A
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polish time[s]
100um/100um
50um/50um
30um/70um
70um/30um
CES-336F series for high planarity and over-polish Window
1:3dil CES-333F-2.5 1:3dil CES-336F-2.4/3.6
1:3dil CES-356F-2.4/3.6
CES-330 F + ADD-106 = CES-336F slurry
Improved Dishing and over-polish margin.
Page 8
Results of patterned wafer polishing (trench oxide)
copyright : Asahi Glass Co.,Ltd.
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0 10 20 30
Dis
hin
g[A
]
over polish[%]
100um/100um
50um/50um
30um/70um
70um/30um
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Dis
hin
g[A
]
over polish[%]
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0 10 20 30
Dis
hin
g[A
]
over polish[%]
100um/100um
50um/50um
30um/70um
70um/30um
Dishing as a function of over-polish
1:3dil CES-333F-2.5 1:3dil CES-336F-2.4/3.6
1:3dil CES-356F-2.4/3.6
/Slurry with ADD-106 showed wider over
polish margin against dishing.
Page 9
copyright : Asahi Glass Co.,Ltd. Page 10
0
250
500
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1000
1250
1500
500u
m L
/S
250u
m L
/S
100u
m L
/S
50um
L/S
25um
L/S
10um
L/S 10
%
20%
30%
40%
50%
60%
70%
Ste
p H
eigh
t [A
]
Si l ica slu r ry on ly
AGC cer ia + si l ica
cer ia on ly process
High selective Poly Si slurry: Two step Ceria slurry process for reduced step height
Conventional Ceria slurry polish for planarization
High selective Poly-Si slurry for poly-Si clearing and stop on oxide.
copyright : Asahi Glass Co.,Ltd.
Poly Si stop Slurry with high oxide rate
copyright : Asahi Glass Co.,Ltd.
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PE [%
]
Step
Hei
ght [
nm]
Removal Amount [nm]
High Planarization Efficiency on Soft Pad
• CL-1524 has good PE.
Equipment/Consumables
・ Equipment: AMAT Mirra
・ Slurry: CL-1524
・ Polishing Pad: softer pad
・ Conditioner:
・ Wafer: Sematech 854 Pattern
Polishing condition
・ Polishing Time: 30, 50 sec
・ Membrane/R-ring Pressure : 2.0 / 4.0 psi
・ Platen/Head rotation speed: 123 / 117 rpm
・ Slurry flow rate: 200 ml/min
・ Conditioning: Ex-situ 30 sec
Line/Space = 0.18/0.18μm
Isolated = 100μm
Line/Space = 10/10μm
Density = 90%
Step Height
PE
CL-1500 Series Cu slurry: CL-1524
End Point
copyright : Asahi Glass Co.,Ltd.
CL-2100 Series Barrier Slurry: Customization for Integration scheme & Design Concept
• Cu removal rate (R/R) is controlled by H2O2 content.
• TEOS R/R is controlled by abrasive content and size.
• Low-k R/R is controlled by variation of suppresser and quantity.
Str
ong
We
ak
Cu
pro
tectio
n
Cu R
em
ova
l Ra
te
CL-214X SeriesCu/TEOS
non-selective type
M
M
CL-213X SeriesCu high
removal rate typeCL-216X SeriesTEOS/Low-k high
selective type
H
H
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CX-1001 Series Front side TSV slurry
• Cu/Ta Selectivity is [email protected], [email protected]
• Cu/Ti Selectivity is [email protected], [email protected]
Removal Rate Removal Profile
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Ta R
emov
al R
ate
[nm
/min
]
X Position [mm]
2.0psi 4.0psi
Membrane
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Ti R
emov
al R
ate
[nm
/min
]X Position [mm]
2.0psi 4.0psi
Membrane
0.5 1.8
22.2
50.4
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0 1 2 3 4
Rem
oval
Rat
e [n
m/m
in]
Membrane [psi]
Cu
Ta
Ti
3228.3 4793.5 Ta
Ti
High Copper Removal Rate and barrier Selectivity
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0
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1
1.2
Abrasive0.05%
Abrasive0.25%
Abrasive0.05%
Abrasive0.25%
APS 0.4% APS 0.5%
Rem
oval
Rate
[um
/m
in]
Cu
TEOS
b-Si
Si/Cu Non-selective slurry (High TEOS RR type)
IT M R.R Platen Head Slurry
[psi] [psi] [psi] [rpm] [rpm] [mL/min]
4 4 4.6 127 123 200
Slurry: CES-330 series for Silicon/Copper polish Polisher: AMAT MirraPad: IC-1000/Suba 400 XY-P (A21)Conditioning: Mitsubishi Material MEC-100, ex-situ 9lbfWafer: bare-Si, Cu, Ta, TEOS Polish Time: bare-Si 5min, Cu, TEOS 1min, Ta 10sec
High TEOS rate without changing the rate of Si and Cu
Ceria Based back side TSV slurry:
copyright : Asahi Glass Co.,Ltd.
UD 1900B Sapphire slurry: Low Cost Removal rate
UD1900B on suede pad maintains high removal rate with wide dilution range.
⇒Slurry cost reduction!
⇒Minimal removal rate change due to slurry dilution shift.
Polishing pressure (psi) Rotation speed (rpm)
UD1900B/suede 3.0 60
copyright : Asahi Glass Co.,Ltd.
Sapphire surface roughness & scratch
UD1900B/suede shows very smooth surface and
no scratches on surface.
SEM images after polishing with UD1900B/suede
Sapphire
wafer
Center
Five points
measurementRa=0.10nm
UD1900B/suedeEquipment
SEM
Zygo
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Ra=0.09nm
18
UD-1405 SiC substrate polish slurry
SiC: good Ra
Surface observation by AFM
( 3’’ , On-axis , Si )
X=5um,Y=5um
Achieves high planarity ( Ra < 0.1nm )