Properties of Ge, Si, and GaAs at 300 oK
Property |
Ge |
Si |
GaAs |
SiO2 |
Atoms or Molecules/cm3 |
4.42 x 1022 |
5.0 x 1022 |
4.42 x 1022 |
2.3 x 1022 |
Atomic of Molecular weight |
72.6 |
28.08 |
144.63 |
60.08 |
Density, g/cm3 |
5.32 |
2.33 |
5.32 |
2.27 |
Breakdown field, V/cm>
| ~10 5 |
~3X10 5 |
~4X10 5 |
~10 7 |
Crystal structure |
Diamond |
Diamond |
Zinc blend |
Amorphous |
Density, g/cm3 |
5.32 |
2.33 |
5.32 |
2.27 |
Dielectric constant |
16 |
11.8 |
13.3 |
3.9 |
Effective density of states:
    Valence band Nv, cm-3 |
6.1 x 1019 |
1.04 x 1019 |
7.0 x 1018 |
  |
Effective density of states:
    Conduction band Nc, cm-3 |
1.04 x 1019 |
2.8 x 1019 |
4.7 x 1017 |
  |
Electron afinity X, V |
4.0 |
4.05 |
4.07 |
0.9 |
Energy gap, eV |
0.68 |
1.12 |
1.43 |
9 |
Intrinsic carrier concentration, ni, cm3 |
2.4 x 1013 |
1.5 x 1010 |
1.8 x 106 |
  |
Lattice constant, nm |
0.5646 |
0.5431 |
0.5653 |
  |
Effective mass:
    Electrons |
me = 0.22m
m*e = 0.12m |
me = 0.33m
m*e = 0.26m |
0.063m |
  |
Effective mass:
    Holes |
mh = 0.31m
m*h = 0.23m |
mh = 0.5m
m*h = 0.16m |
0.05m |
  |
Intrinsic mobility:
    Electron, cm2/V-s |
3900 |
1500 |
8600 |
  |
Intrinsic mobility:
    Hole, cm2/V-s |
1900 |
450 |
400 |
  |
Temperature coefficient of expansion, oC-1 |
5.8 x 10-6 |
2.6 x 10-6 |
6.8 x 10-6 |
5 x 10-6 |
Thermal conductivity, W/cm -oC |
0.6 |
1.5 |
0.46 |
0.01 |
|
Physical Constants
Constant |
Symbol |
Magnitude |
Avagadro's Number |
NA |
6.023 x 1023 molecules/mole |
Boltzmann's constant |
k |
1.38 x 10-23 J/K = 8.62 x 10-5 eV/K |
Electronic charge |
q |
1.6 x 10-19 C |
Electronvolt |
eV |
1.6 x 10-19 J |
Planks constant |
h |
6.625 x 10-34 J-s |
Thermal voltage at 300 oK |
Vt |
25.8 mV |
Velocity of light |
c |
3 x 1010 cm/s |
Permeability of free space |
uo |
1.257 x 10-8 H/cm |
Permittivity of free space |
eo |
8.854 x 10-14 F/cm |
Free-electron mass |
m |
9.1 x 10-31 kg |
Carrier Mobility in Silicon
Doping cm-3 |
Electron Mobility (cm2 V-sec) |
Hole Mobility (cm2 V-sec) |
1014 | 1500 | 450 |
1015 | 1500 | 450 |
1016 | 1400 | 440 |
1017 | 1200 | 410 |
1018 | 800 | 200 |
1019 | 200 | 150 |
1020 | 90 | 50 |
Actual mobility values will vary.
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