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 (5.0 x 10-9cm2/s at 1195C and 1.2 x 10-10cm2/s at 1000C) 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 187

Diffusivity of O in Czochralski-Type Si

 

T (C)

D (cm2/s)

340

2.7 x 10-20

340

2.2 x 10-20

325

7.0 x 10-21

300

1.4 x 10-21