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 40) could be described by:
D(cm2/s) = 170 exp[-1.2(eV)/kT]
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
Table 40
Diffusivity of H in Si
T (C) | D (cm2/s) |
225 | 7.8 x 10-11 |
235 | 1.6 x 10-10 |
235 | 4.0 x 10-10 |
250 | 4.5 x 10-10 |
250 | 5.4 x 10-10 |
275 | 1.3 x 10-9 |
275 | 1.7 x 10-9 |
300 | 1.6 x 10-8 |
300 | 2.3 x 10-8 |
325 | 1.2 x 10-8 |
325 | 1.8 x 10-8 |
330 | 4.9 x 10-9 |
330 | 7.6 x 10-9 |
350 | 5.6 x 10-8 |
350 | 7.6 x 10-8 |