Migration in amorphous and polycrystalline Si-on-monocrystal systems during rapid thermal annealing and furnace annealing was studied. It was found that changes in microstructure during annealing played a major role in determining diffusion profiles in the substrate, as well as in the polycrystalline Si layer. In the case of As doping, drive-in diffusion resulted in a much larger grain microstructure in as-deposited amorphous Si than in as-deposited polycrystalline Si. This led to the formation of shallower junctions in the first case. At high annealing temperatures, the native interfacial oxide disintegrated, caused epitaxial realignment of the polycrystalline Si film, and led to enhanced diffusion in the substrate.

K.Park, S.Batra, S.Banerjee, G.Lux, T.C.Smith: Journal of Applied Physics, 1991, 70[3], 1397-404