The out-diffusion profiles of nitrogen in silicon were measured using secondary ion mass spectrometry to determine its diffusion coefficient at 800 to 1200C. The total amount of nitrogen out-diffusion agreed with the change in infra-red absorption by heat treatment. The results for the diffusion coefficient of nitrogen could be described by:

D(cm2/s) = 2.7 x 103exp[−2.8(eV)/kT]

These values were five orders of magnitude larger than those given by the reported expression:

D(cm2/s) = 8.7 x 10-1exp[−3.29(eV)/kT]

Nitrogen–nitrogen pair‐like molecules corresponded to the former values, and substitutional nitrogen atoms to the latter ones. These two types of nitrogen in silicon might permit clarification of the various effects of nitrogen, such as strengthening of crystals and the suppression of swirls and D‐defect generation.

Diffusion Coefficient of a Pair of Nitrogen Atoms in Float‐Zone Silicon. T.Itoh, T.Abe: Applied Physics Letters, 1988, 53, 39