A review was presented of progress in the understanding of the mechanisms of Ga self-diffusion and impurity diffusion in GaAs, and of the disordering of GaAs/AlGaAs superlattices. The self-diffusion of Ga, and Al-Ga interdiffusion, under intrinsic and n-doping conditions were governed by triply negatively charged group-III sub-lattice vacancies (VGa3-) while, under heavy p-doping conditions, they were probably governed by the doubly positively charged self-interstitial, IGa2+. The GaAs/AlGaAs superlattice disordering enhancement which was observed under n-doping by Si or Te was attributed to the Fermi-level effect, which increased the VGa3- concentration. An elusive disordering enhancement under p-doping by Zn or Be was attributed to the combined effects of the Fermi level, which increased the IGa2+ concentration, and to dopant in-diffusion or out-diffusion induced IGa2+ supersaturation or undersaturation, respectively. In parallel with the Ga self-diffusion mechanism in GaAs, diffusion of the Si donor atoms which occupied Ga sites was also governed mainly by VGa3-. Meanwhile, Si acceptor atoms which occupied As sites (a small fraction of the total) diffused via a negatively charged As sub-lattice point-defect species. The interstitial-substitutional p-type dopants, Zn and Be, diffused via the kick-out mechanism. Their diffusion induced IGa2+ supersaturation and undersaturation, respectively, under in-diffusion and out-diffusion conditions.

T.Y.Tan, U.Gösele, S.Yu: Critical Reviews in Solid State and Materials Science, 1991, 17[1], 47-106