The dependence of the diffusion coefficient upon the growth conditions of doped hydrogenated amorphous material (table 26) 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.

Dependence of Hydrogen Diffusion On Growth Conditions in Hydrogenated Amorphous Silicon. R.A.Street, C.C.Tsai: Philosophical Magazine B, 1988, 57[5], 663-9

Table 26

Effect of P and As upon H Diffusion in Si