Transcript DIRECT MEASUREMENT OF PLANARIZATION LENGTH FOR …

DIRECT MEASUREMENT OF PLANARIZATION LENGTH FOR
COPPER CHEMICAL MECHANICAL POLISHING (CMP)
PROCESSES USING A LARGE PATTERN TEST MASK.
Paul Lefevre, Albert Gonzales, Tom Brown, Gerald Martin,International SEMATECH, Austin, TX;
Tamba Tugbawa, Tae Park, Duane Boning, Microsystems Technology Laboratories, MIT, Cambridge, MA;
Michael Gostein, Philips Analytical, Natick, MA;
John Nguyen, SpeedFam-IPEC, Phoenix, AZ.
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 1
Agenda
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Introduction
Pre CMP topography
International Sematech / MIT Mask 862 design
Wafer process and metrology
Planarization Length definition
Planarization Length on different process
Planarization Length on different consumables
Conclusion
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 2
Introduction
• Visual observation copper residue are more or less pattern
dependent (Qualitative)
• Feature size design / Pre CMP topography size
• Develop a direct qualitative method for planarization
distance measurement.
• Help industry with having access to this mask International
Sematech / MIT 862 (Semiconductor and CMP suppliers)
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 3
Pre CMP topography
50 um copper line, 50 um space
1 um copper line, 1 um space
0.25 um copper line, 0.25 um space
9 um copper line, 1 um space
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 4
Pre CMP topography consequence
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 5
Wafer layout
20000
25000
5000
5000
2500
3000
1500, 1250, 1000, 800, 600, 500, 400, 300
2500
1500, 1250, 1000, 800, 600, 500, 400, 300
3000
5000
5000
8000
8000
8000
8000
2500
1500, 1250, 1000, 800, 600, 500, 400, 300
3000
5000
8000
2500
1500, 1250, 1000, 800, 600, 500, 400, 300
2500
3000
3000
1500, 1250, 1000, 800, 600, 500, 400, 300
Sm a l l
fe a t u re s
4000
2000
6000
4000
2000
6000
4000
2000
6000
4000
2000
6000
4000
2000
6000
12500
15000
10000
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 6
Mask layout
5000
8000
2500
1500,
1250,
1000,
3000
800, 600, 500, 400,300,250,200,150,125
Small
features
(5mm x 4mm)
4000
2000
6000
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 7
Small structures
100,
Small features
(5mm x 4mm)
80, 60, 50, 40,30,25,20,15,12.5,10,8,6,5,4,3, 2.5,2,1.5,1.25,1
Line width = 20;
Line space = 1,
3, 5, 10, 15, 20,
30, 50, 75, 100
(0.509 mm x
1.200 mm)
Line width =
15;
Line space
= 1, 3, 5,
10, 15, 20,
30, 50, 75,
100
(0.459 mm
x 1.200
mm)
Line width
= 10;
Line
space = 1,
3, 5, 10,
15, 20, 30,
50, 75,
100
(0.409 mm
x 1.200
mm)
Line
width =
5;
Line
space =
1, 3, 5,
10, 15,
20, 30,
50, 75,
100
(0.359
mm x
1.200
mm)
Line
width =
1;
Line
space
= 1, 3,
5, 10,
15, 20,
30, 50,
75,
100
(0.319
mm x
1.200
mm)
Line width = 50;
Line space = 1, 3, 5,
10, 15, 20, 30, 50, 75,
100
(0.809 mm x 1.200
mm)
Line width = 100;
Line space = 1, 3, 5, 10, 15, 20, 30, 50, 75, 100
(1.309 mm x 1.200 mm)
Line width = 1, 1.5,
3,
5,
10, 15,
30,
50,
100
Line lenght = 1, 1.5, 3, 5, 10, 15, 30, 50, 100, 150, 300,
500, 1000
(1.815 mm x 3.965 mm)
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 8
Wafer process
Ta
Cu
TEOS
SiO2
Silicon
Copper Thickness is 2X trench height
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 9
Metrology
Measurements
performed on
Philips Impulse 300
20000
25000
15 measures per
Structure
-5 left
-5 center
-5 right
5000
5000
2500
3000
1500, 1250, 1000, 800, 600, 500, 400, 300
2500
1500, 1250, 1000, 800, 600, 500, 400, 300
3000
5000
5000
8000
8000
8000
8000
2500
1500, 1250, 1000, 800, 600, 500, 400, 300
3000
5000
8000
2500
1500, 1250, 1000, 800, 600, 500, 400, 300
2500
3000
3000
1500, 1250, 1000, 800, 600, 500, 400, 300
Sm a l l
fe a t u re s
4000
2000
6000
4000
2000
6000
4000
2000
6000
4000
2000
6000
4000
2000
6000
12500
15000
10000
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 10
Results
Thickness removed in the top area
Thickness removed (A)
7000
6000
1, 853A
5000
2, 2111A
4000
3, 3400A
3000
4, 3400A
2000
5, 4848A
1000
0
100
6, 5748A
1000
10000
100000
Thickness removed (A)
Thickness removed in the bottom area
7000
6000
1, 853A
5000
4000
2, 2111A
3000
2000
4, 3400A
1000
0
100
6, 5748A
3, 3400A
5, 4848A
1000
Feature size (um)
5000
1, 853A
4000
2, 2111A
3, 3400A
3000
4, 3400A
2000
5, 4848A
1000
6, 5748A
10000
Feature size (um)
Top - Bottom
100000
Planarization efficiency in
% (1 - RR bot / RR top)
Delta Copper thickness (A)
Planarization efficiency
6000
1000
100000
Feature size (um)
Copper removal Delta Top - Bottom
0
100
10000
120%
1, 853A
100%
2, 2111A
80%
3, 3400A
60%
4, 3400A
40%
5, 4848A
20%
6, 5748A
0%
100
1000
10000
100000
Feature size (microns)
PE = 1 – Bottom / Top
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 11
Results
Delta Copper thickness (A)
Copper removal Delta Top - Bottom
6000
5000
1, 853A
4000
2, 2111A
3, 3400A
3000
4, 3400A
2000
5, 4848A
1000
6, 5748A
0
100
1000
10000
100000
Log Scale
Feature size (um)
Minimum Planarization Length
Maximum Planarization Length
Average planarization Length
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 12
Planarization Lengths
Average Planarization Length
Maximum Planarization Length = Minimum Feature size were removal bottom equal removal top
Or
Maximum Planarization Length = Minimum Feature size were planarization Efficiency is zero
Minimum Planarization Length = Maximum Feature size where removal bottom is zero
Or
Minimum Planarization Length = Maximum Feature size where planarization efficiency is 1
Average Planarization Length on a Log scale diagram is = Exp ( Average (Min PL, Max PL))
Average planarization Length =
(Min PL) x (Max PL)
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 13
Consumable comparison
4500
4000
3500
3000
2500
2000
1500
1000
500
0
Removal on the Bottom
P1S1 Top
P2S1 Top
P2S2 Top
P3S3 Top
P4S4 Top
0
5000
Thickness (A)
Thickness (A)
Removal on the Top
10000 15000 20000 25000 30000
4500
4000
3500
3000
2500
2000
1500
1000
500
0
P1S1 Bottom
P2S1 Bottom
P2S2 Bottom
P3S3 Bottom
P4S4 Bottom
0
10000
Feature size (um)
30000
Planarization Efficiency
100%
P1S1 Delta
P2S1 Delta
P2S2 Delta
P3S3 Delta
P4S4 Delta
Efficiency (%)
Thickness (A)
Removal delta Top - Bottom
4500
4000
3500
3000
2500
2000
1500
1000
500
0
20000
Feature size (um)
80%
P1S1 PE
60%
P2S1 PE
P2S2 PE
40%
P3S3 PE
20%
P4S4 PE
0%
0
5000 10000 15000 20000 25000 30000
Feature size (um)
0
5000
10000 15000 20000 25000 30000
Feature size (um)
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 14
Consumable comparison
4500
4000
3500
3000
2500
2000
1500
1000
500
0
100
Removal on the Bottom
P1S1 Top
P2S1 Top
P2S2 Top
P3S3 Top
P4S4 Top
1000
10000
Thickness (A)
Thickness (A)
Removal on the Top
100000
4500
4000
3500
3000
2500
2000
1500
1000
500
0
100
Feature size (um)
P2S2 Bottom
P3S3 Bottom
P4S4 Bottom
1000
10000
100000
Planarization Efficiency
100%
P1S1 Delta
P2S1 Delta
P2S2 Delta
P3S3 Delta
P4S4 Delta
Efficiency (%)
Thickness (A)
P2S1 Bottom
Feature size (um)
Removal delta Top - Bottom
4500
4000
3500
3000
2500
2000
1500
1000
500
0
100
P1S1 Bottom
80%
P1S1 PE
60%
P2S1 PE
P2S2 PE
40%
P3S3 PE
20%
P4S4 PE
0%
1000
10000
Feature size (um)
100000
100
1000
10000
100000
Feature size (um)
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 15
Consumable comparison
Process
Symbol
P1S1
P2S1
P2S2
P3S3
P4S4
Down
Force
(psi)
Carrier
Speed
(rpm)
Table
Speed
(rpm)
4
4
4
2
75
75
75
100
75
75
75
100
Slurry
Pad
Type
Tool
Type
Type
A
A
B
C
D
Max PL Min PL
(um)
Stacked
Solo
Solo
Stacked
Solo**
Rotary
Rotary
Rotary
Rotary
Orbital
9000
28000
39690
39690
50009
(um)
1250
1250
1250
2000
1000
Av. PL
(um)
3354
5916
7044
8910
7072
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 16
Process comparison
Removal on the Top
Removal on the Bottom
4500
3500
14 ppn
15 pnp
16 pnn
17 npp
3000
2500
2000
1500
1000
18 npn
19 nnp
20 nnn
500
0
0
10000
20000
Thickness (A)
Thickness (A)
4500
4000
12 ooo
13 ppp
4000
12 ooo
13 ppp
3500
3000
14 ppn
15 pnp
16 pnn
2500
2000
17 npp
18 npn
19 nnp
20 nnn
1500
1000
500
0
30000
0
5000
Feature size (um)
Feature size (um)
Planarization efficiency Fujimi RD-98052
4500
4000
3500
3000
2500
2000
1500
1000
500
0
12 ooo
13 ppp
14 ppn
15 pnp
16 pnn
17 npp
18 npn
10000
20000
Feature size (um)
30000
19 nnp
20 nnn
Planarization efficiency in %
(1 - RR bot / RR top)
Thickness (A)
Removal delta Top - Bottom
0
10000 15000 20000 25000 30000
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
12 ooo
13 ppp
14 ppn
15 pnp
16 pnn
17 npp
18 npn
0
5000 10000 15000 20000 25000 30000
19 nnp
20 nnn
Feature size (microns)
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 17
Process comparison
Removal on the Top
Removal on the Bottom
4500
Thickness (A)
3500
3000
2500
2000
1500
1000
500
4500
Thickness (A)
12 ooo
13 ppp
14 ppn
15 pnp
16 pnn
17 npp
18 npn
19 nnp
20 nnn
4000
12 ooo
13 ppp
14 ppn
15 pnp
16 pnn
17 npp
18 npn
19 nnp
20 nnn
4000
3500
3000
2500
2000
1500
1000
500
0
0
100
1000
10000
100000
100
1000
Feature size (um)
13 ppp
14 ppn
15 pnp
16 pnn
17 npp
18 npn
19 nnp
10000
Feature size (um)
100000
20 nnn
Planarization efficiency in %
(1 - RR bot / RR top)
Thickness (A)
Planarization efficiency Fujimi RD-98052
12 ooo
1000
100000
Feature size (um)
Removal delta Top - Bottom
4500
4000
3500
3000
2500
2000
1500
1000
500
0
100
10000
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
100
12 ooo
13 ppp
14 ppn
15 pnp
1000
10000
100000
16 pnn
17 npp
18 npn
19 nnp
20 nnn
Feature size (microns)
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 18
Process comparison
Slurry
Process Down Carrier Table
Slurry Pad Type
flow
Force Speed Speed
Symbol (psi) (rpm) (rpm) (ml/min) Type
ooo
ppp
ppn
pnp
pnn
npp
npn
nnp
nnn
2
3
3
3
3
1
1
1
1
65
100
100
30
30
100
100
30
30
65
100
100
30
30
100
100
30
30
125
200
50
200
50
200
50
200
50
C
C
C
C
C
C
C
C
C
Stacked
Stacked
Stacked
Stacked
Stacked
Stacked
Stacked
Stacked
Stacked
Tool
Type
Rotary
Rotary
Rotary
Rotary
Rotary
Rotary
Rotary
Rotary
Rotary
Max PL Min PL Av. PL
(um)
(um)
(um)
20000
12500
12500
8000
8000
39375
39375
39375
39375
2000
2000
2000
2000
2000
3000
3000
2500
2500
6325
5000
5000
4000
4000
10869
10869
9922
9922
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 19
Process comparison
Low Planarization Length
Very high Planarization Length
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 20
Conclusion
• New International Sematech / MIT mask 862
allow a direct measure of planarization Length
• Definition of Planarization Length
• Wafers mask 862 available – In public domain
Copper CMP Planarization Length - MRS 2001 - April 19th, 2001 – Paul Lefevre – Page 21