The diffusion of H in radio-frequency sputter-deposited undoped or B-doped amorphous material was studied by means of secondary ion mass spectrometric profiling of annealed multi-layers. It was found that long-range atomic H motion appeared to be suppressed in undoped amorphous hydrogenated material with an excess micro-void content. However, in amorphous hydrogenated multi-layers which exhibited diffusion, the diffusion constant exhibited a power-law time dependence:

D(t) = kDo(wt)-n

where n was between 0.2 and 0.9. These results were explained in terms of relaxation processes and the dynamics of floating and dangling bonds in amorphous hydrogenated Si.

R.Shinar, S.Mitra, X.L.Wu, J.Shinar: Journal of Non-Crystalline Solids, 1989, 114[1], 220-2