A review of previous data indicated that the self-diffusion of Ga involved either the vacancy or the interstitialcy mechanism. A switch from one to the other could occur, due to variations in the Fermi level or the As pressure. The self-diffusion appeared to be associated with Ga vacancies with a charge of -3, in the case of n-type material, or with Ga interstitials with a charge of 2 in the case of p-type material. In the case of intrinsic material, a commonly observed V-form of the Ga diffusivity versus As pressure plot was suggested to be consistent with the 2 diffusion mechanisms. It was noted that it was a simple matter to predict the near-equilibrium Ga diffusivity on the basis of a single intrinsic Ga diffusion coefficient. A model was developed which linked the changeover in Ga diffusivity and electron concentration at high donor concentrations.

R.M.Cohen: Journal of Electronic Materials, 1991, 20[6], 425-30