The relaxation of stress-induced dichroism of the 9000nm O infra-red absorption band was investigated in samples of Czochralski material which had been annealed in a H plasma at temperatures of between 225 and 350C. It was found that the in-diffusion of H atoms enhanced the rate of O diffusion, so that dichroism disappeared gradually from the external surfaces. It was deduced that the H diffusivity (table 57) could be described by:

D(cm2/s) = 1.70 x 102exp[-1.2(eV)/kT]

Hydrogen Diffusion and the Catalysis of Enhanced Oxygen Diffusion in Silicon at Temperatures below 500C. R.C.Newman, J.H.Tucker, A.R.Brown, S.A.McQuaid: Journal of Applied Physics, 1991, 70[6], 3061-70. See also: Materials Science Forum, 1992, 83-87, 87-92