The segregation of Sb at moving crystalline/amorphous (001) interfaces, during the preparation of δ-doped layers, was studied. The use of X-ray reflectivity measurements revealed a broadening of the δ-doping profile, due to segregation during the crystallization of amorphous Si. On the basis of ion back-scattering and channelling data, it was deduced that the bulk diffusion coefficients were too low to explain the observed segregation behavior. The broadening was attributed to enhanced diffusion at the amorphous/crystalline interface. The interfacial diffusion coefficient was at least 2 orders of magnitude higher than the diffusivity in bulk amorphous material.

W.F.J.Slijkerman, P.M.Zagwijn, J.F.Van der Veen, G.F.A.Van de Walle, D.J.Gravesteijn: Journal of Applied Physics, 1991, 70[4], 2111-6