It was recalled that, when p-n junctions were formed by doping with an element that diffused via a dissociative mechanism, dopant diffusion was suppressed and dopants could pile up near to the junction; at well above their original concentration. Calculations confirmed this behavior, if no local neutrality was assumed. The results agreed well with published experimental data on Zn diffusion in the present material. It was noted that the increased built-in electric field, due to this pile-up, was expelled almost entirely to the side of the junction without the pile-up. It was suggested that this effect had important implications for devices, which contained thin and/or small regions that were doped with such elements, because such regions might become completely depleted.

I.Lyubomirsky, V.Lyahovitskaya, D.Cahen: Applied Physics Letters, 1997, 70[5], 613-5