Behavior of Nickel as an Impurity in Silicon

Abstract

Distribution and precipitation of nickel in silicon and effect of nickel upon resistivity were studied by use of ⁶³Ni, by an infrared, an optical and an X-ray diffraction microscopes and by four points method. The followings are concluded. During the heating nickel is dissolved interstitially to the solubility. Diffusion constant of the interstitial nickel is 10^-4~-5 cm²/sec. Its migration energy is very small and may be comparable with that of an interstitial silicon reported by Watkins. During the cooling the interstitial nickel precipitates at the surface and also in the interior. Number of an electrically active nickel is very small compared to that of the interstitial nickel. Some kind of lattice defect is formed at a precipitation site. It is fairly stable against the heat treatment and plays a role of nucleus of the precipitates on and after the second heat treatment.