42
S. J. Mukhopadhyay et al.
Table 1 Design parameters
Base
material
Design
frequency,
f d (GHz)
n-layer
thickness,
W n (nm)
p-layer
thickness,
W p (nm)
n-layer
doping
concentration,
N D (× 10 23
m −3 )
p-layer
doping
concentration,
N A (× 10 23
m −3 )
n + - and
p + -layer
doping
concentrations,
N Sub (× 10 26
m −3 )
Bias
current
density,
J 0 (×
10 8 A
m −2 )
Si
94
400.0
380.0
1.20
1.25
1.00
3.40
140
280.0
245.0
1.80
2.10
1.00
5.80
220
180.0
160.0
3.95
4.59
1.00
14.50
300
132.0
112.0
6.00
7.30
1.00
24.50
500
72.0
70.0
15.0
16.2
1.00
55.00
3C-SiC
94
410.0
410.0
2.50
2.50
1.00
6.00
140
300.0
300.0
5.00
5.00
1.00
16.00
220
200.0
200.0
8.00
8.00
1.00
30.00
300
160.0
160.0
11.00
11.00
1.00
55.00
500
103.0
103.0
16.50
16.50
1.00
104.00
1000
57.0
57.0
23.50
22.50
1.00
135.00
Type-IIb
diamond
94
780.0
780.0
0.460
0.530
1.00
4.00
140
530.0
530.0
0.810
0.870
1.00
7.50
220
320.0
320.0
1.350
1.490
1.00
13.00
300
220.0
220.0
2.050
2.220
1.00
17.00
500
120.0
120.0
3.750
4.100
1.00
25.00
1000
52.0
52.0
9.500
10.00
1.00
39.00
1500
30.0
30.0
36.00
37.00
1.00
48.00
chapter. The published literatures from which those parameters have been incorporated in the simulation study have also been mentioned in that chapter [14–20]. The
earlier chapter also provides a brief note on the design of the mm-wave and THz
DDR IMPATTs. However, for the sake of convenience of the readers, the design
parameters are repeated once again in Table 1.
4 Small-Signal Noise Model
The avalanche noise simulation of an ATT device starts with the calculation of spatial
distribution of noise field e n (x, x
), where x is the space coordinate at which e n is
calculated and x
is the space coordinate at which an arbitrary noise supply γ (x
) is
assumed to be present) within the space charge region of the device. Small-signal
noise field is essentially a complex quantity having real and imaginary components,
i.e., e nr (x, x
) and e ni (x, x
), respectively. Two second-order partial differential equations involving e nr and e ni can be derived under small-signal circumstance [9]; those
have to be solved simultaneously subject to the boundary conditions imposed at the
edges of the space charge layer, from which e nr (x, x
) and e ni (x, x
) can be obtained.
This solution provides spatial distributions of e nr (x, x
) and e ni (x, x
) for a particular
S. J. Mukhopadhyay et al.
Table 1 Design parameters
Base
material
Design
frequency,
f d (GHz)
n-layer
thickness,
W n (nm)
p-layer
thickness,
W p (nm)
n-layer
doping
concentration,
N D (× 10 23
m −3 )
p-layer
doping
concentration,
N A (× 10 23
m −3 )
n + - and
p + -layer
doping
concentrations,
N Sub (× 10 26
m −3 )
Bias
current
density,
J 0 (×
10 8 A
m −2 )
Si
94
400.0
380.0
1.20
1.25
1.00
3.40
140
280.0
245.0
1.80
2.10
1.00
5.80
220
180.0
160.0
3.95
4.59
1.00
14.50
300
132.0
112.0
6.00
7.30
1.00
24.50
500
72.0
70.0
15.0
16.2
1.00
55.00
3C-SiC
94
410.0
410.0
2.50
2.50
1.00
6.00
140
300.0
300.0
5.00
5.00
1.00
16.00
220
200.0
200.0
8.00
8.00
1.00
30.00
300
160.0
160.0
11.00
11.00
1.00
55.00
500
103.0
103.0
16.50
16.50
1.00
104.00
1000
57.0
57.0
23.50
22.50
1.00
135.00
Type-IIb
diamond
94
780.0
780.0
0.460
0.530
1.00
4.00
140
530.0
530.0
0.810
0.870
1.00
7.50
220
320.0
320.0
1.350
1.490
1.00
13.00
300
220.0
220.0
2.050
2.220
1.00
17.00
500
120.0
120.0
3.750
4.100
1.00
25.00
1000
52.0
52.0
9.500
10.00
1.00
39.00
1500
30.0
30.0
36.00
37.00
1.00
48.00
chapter. The published literatures from which those parameters have been incorporated in the simulation study have also been mentioned in that chapter [14–20]. The
earlier chapter also provides a brief note on the design of the mm-wave and THz
DDR IMPATTs. However, for the sake of convenience of the readers, the design
parameters are repeated once again in Table 1.
4 Small-Signal Noise Model
The avalanche noise simulation of an ATT device starts with the calculation of spatial
distribution of noise field e n (x, x
), where x is the space coordinate at which e n is
calculated and x
is the space coordinate at which an arbitrary noise supply γ (x
) is
assumed to be present) within the space charge region of the device. Small-signal
noise field is essentially a complex quantity having real and imaginary components,
i.e., e nr (x, x
) and e ni (x, x
), respectively. Two second-order partial differential equations involving e nr and e ni can be derived under small-signal circumstance [9]; those
have to be solved simultaneously subject to the boundary conditions imposed at the
edges of the space charge layer, from which e nr (x, x
) and e ni (x, x
) can be obtained.
This solution provides spatial distributions of e nr (x, x
) and e ni (x, x
) for a particular