The out-diffusion of O, from Czochralski wafers which had been annealed at 1000 or 1200C in a H ambient, was studied by means of secondary ion mass spectroscopy. The expression,

D(cm2/s) = 141 exp[-3.1(eV)/kT]

was deduced by fitting the O secondary ion mass spectroscopy profile, and the diffusivities (table 63) were significantly higher than expected. This H enhancement effect was found at temperatures which were much greater than those (below 500C) which were reported in the literature. The enhancement was attributed to direct interaction between in-diffused H and interstitial O atoms. The O diffusivity which was deduced from H solubility and diffusivity data was in reasonable agreement with the experimental results.

L.Zhong, F.Shimura: Journal of Applied Physics, 1993, 73[2], 707-10

Table 63

Diffusivity of O in Si