Diffusion profiles of zinc in indium phosphide

Abstract

A series of experiments is described in which radio-tracer Zn was diffused into n-type InP over a wide range of experimental conditions. Diffusions were carried out in the temperature range 650-900 degrees C, for varying times of diffusion, and for a variety of ambient vapour pressures. Both chemical and isoconcentration diffusions were performed, and it was found that the diffusion constants for chemical diffusion are much smaller than those for isoconcentration experiments. A model is proposed in which most of the Zn occurs in the InP in the form of the complex (VPZnInV P). Zn atoms also occupy interstitial and substitutional sites, the latter giving rise to the observed p-type conductivity.