It was recalled that metallic ions which were introduced into such semiconductors could diffuse either as interstitial donors, or build up complexes with native shallow acceptors. A method which was based upon donor diffusion into the material from an accumulation zone, could be used to determine the donor diffusion coefficients. However, the internal induced electric field that resulted from the differing mobilities of holes and charged donors greatly enhanced diffusion in strongly compensated semiconductors. Simulations of diffusion, which took account of the association/dissociation of complexes and of an induced electric field, yielded new information. One result was that ion-pairing acted as a brake on free donor diffusion, while an induced electric field enhanced diffusion.

B.O.Wartlick, C.Blanchard, J.F.Barbot: Philosophical Magazine B, 1998, 78[1], 79-86