Basic Bipolar Process Description

1
Basic Bipolar Process Description

• Bipolar Process Flow
• Vertical npn
• Lateral pnp
• JFET
• Prepared by Randy Geiger, September 2001

2
Bipolar Process Flow
Metalization
Oxidation
Bipolar Process Flow
Contact Openings
Isolation Diffusion
p-base diffusion
n emitter diffusion
n-epitaxy
Buried collector
n buried collector implant
P-substrate
3
Base
Emitter
Collector
Buried collector
n buried collector implant
Vertical npn BJT
4
Lateral pnp Modification
Lateral pnp BJT
5
JFET Modification
G
S
D
6
BJT Layout and Area Issues

• BJT Layout
• BJT Area Requirements
• Comparison of Area between MOS and Bipolar
  Processes

7
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
15
20
25
30
35
40
45
50
55
8
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
15
20
25
30
3l
35
40
45
50
55
9
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
15
20
25
30
3l
2l
35
40
45
50
55
10
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
15
20
15l
25
30
3l
2l
35
40
45
50
55
11
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
15
20
25
2l
30
3l
2l
35
40
45
50
55
12
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
15
20
25
30
3l
2l
35
40
45
50
55
13
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
15
20
25
30
3l
2l
35
40
45
50
55
14
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
15
20
25
30
3l
2l
35
40
45
50
55
15
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
15
20
25
30
3l
2l
4l
35
40
45
50
55
16
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
15
20
12l
25
2l
2l
30
6l
3l
2l
4l
35
NOT TO SCALE
Note 24l required Between p-base and isolation
diffusion
40
45
50
55
17
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
Note Not to vertical Scale
10
15
20
12l
25
58l
2l
30
6l
3l
2l
2l
35
Note 24l required Between p-base and isolation
diffusion
40
45
50
55
18
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
Note Not to vertical Scale
10
15
20
12l
25
2l
30
6l
3l
2l
2l
35
Note 24l required Between p-base and isolation
diffusion
40
45
50
55
19
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
15
67l
20
62l
25
30
35
40
Note Not to vertical Scale
45
50
55
20
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
15
67l
20
62l
25
30
35
40
Bounding Area 4154l2
Note Not to vertical Scale
45
50
55
21
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
Comparison with Area for n-channel
MOSFET in Bulk CMOS
15
20
16l
25
13l
30
35
Bounding Area 208l2
40
45
50
55
22
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
Minimum-Sized MOSFET
15
20
14l
25
30
35
Bounding Area 168l2 Active Area 6l2
40
45
50
55
23
1
5
10
15
20
25
30
35
40
45
50
60
55
70
65
75
1
5
10
15
67l
20
62l
25
30
35
40
MOSFET
BJT
45
50
Note Not to vertical Scale
55
24
Area Comparison between BJT and MOSFET

• BJT Area 4154 l2
• n-channel MOSFET Area 168 l2
• Area Ratio 251

25
Thats all folks!