The diffusion of Zn into Te-doped samples was studied as a function of time, temperature, and Sb over-pressure. The overall Zn profiles, as well as carrier concentration profiles, were measured. The results indicated the operation of a substitutional-interstitial vacancy (Frank-Turnbull) or kick-out (Gosele-Morehead) mechanism; although there was insufficient evidence to decide between them. There was also an inverse dependence of the diffusivity upon the Sb over-pressure. This was explained in terms of a Zn diffusion that was superposed on Ga vacancy diffusion. It was noted that Te doping appeared to have little effect upon diffusion, due to its low level when compared to that of Zn. Moreover, at high Zn concentrations, the profiles indicated the presence of an additional component that was associated with a non-electrically active Zn species which had a small strongly temperature-dependent diffusion coefficient.

G.J.Conibeer, A.F.W.Willoughby, C.M.Hardingham, V.K.M.Sharma: Journal of Electronic Materials, 1996, 25[7], 1108-12