The Zn was diffused into GaAs through anodic oxide layers with various thicknesses and densities. Electrochemical profiling was used to determine the electrically active Zn concentration and the diffusion depth. It was found that the depth of the junction varied inversely with the thickness and density of the oxide. However, the surface concentration appeared to be independent of the oxide thickness or density and attained a value which was identical to that which was found for diffusion into a bare GaAs sample. The results demonstrated that the most important effect of the oxide was to delay the introduction of Zn into the lattice. Thus, the anodic oxide could not be used as a mask or a Zn concentration attenuator.

H.Cutlerywala, R.J.Roedel: Journal of the Electrochemical Society, 1994, 141[6], 1639-43