It was shown here that Au diffused back and forth, between a highly P-doped layer and the bulk of the material, when the annealing temperature was varied. This behavior was investigated by using secondary ion mass spectroscopy to study Au within the gettering layer, and by using deep-level transient spectroscopy to estimate the Au content of the bulk. It was found that the gettered Au was located within the P profile, but was not gettered to the surface. No internal gettering or out-diffusion of Au was observed when the Au concentration was below the solubility limit. The results could not be described by using a simple segregation model unless the Au solubility in the bulk was modified by taking account of a possible supersaturation of Si self-interstitials.

E.O.Sveinbjörnsson, O.Engström, U.Södervall: Materials Science Forum, 1994, 143-147, 1641-6