The dependence of the diffusion coefficient upon the growth conditions of doped hydrogenated amorphous material (table 162) was measured by using secondary ion mass spectrometry. A markedly enhanced diffusivity (4.9 x 10-13 at 240C and 4.8 x 10-15cm2/s at 240C) was found in material with a columnar microstructure, due to the preferential motion of H along the columns. Increasing the deposition temperature of non-columnar material resulted in a higher diffusion coefficient and a lower H concentration. No significant change in the diffusivity was found for different n-type dopants.
R.A.Street, C.C.Tsai: Philosophical Magazine B, 1988, 57[5], 663-9
Diffusivity of H in Various Types of Si
Type | Temperature (C) | D (cm2/s) |
polycrystalline | 305 | 1.6 x 10-8 |
polycrystalline | 245 | 1.1 x 10-8 |
polycrystalline | 200 | 3.7 x 10-9 |
polycrystalline | 155 | 9.0 x 10-10 |
float-zone | 305 | 6.1 x 10-10 |
float-zone | 245 | 3.1 x 10-9 |
float-zone | 200 | 6.1 x 10-10 |
float-zone | 155 | 1.5 x 10-10 |
Czochralski | 305 | 5.6 x 10-11 |
Czochralski | 245 | 9.0 x 10-10 |
Czochralski | 200 | 2.0 x 10-10 |
Czochralski | 155 | 4.1 x 10-11 |