Polycrystalline thin films were deposited onto Si (111) wafers by evaporation under a vacuum of 2 x 10-6mbar. The concentration profiles in heat-treated specimens were obtained by Auger-electron depth profiling. Heat treatment was carried out in a vacuum furnace (4 x 10-6mbar) at 473 to 773K. It was found, using a modified Whipple model, that the grain boundary diffusivity could be described by:

D (cm2/s) = 3 x 10-4 exp[-0.94(eV)/kT]

It was concluded that interdiffusion in this system was characterized by type-B kinetics, and that grain-boundary diffusion played a predominant role in mass transport.

A.M.Abdul-Lettif: Surface and Interface Analysis, 2003, 35[5], 429-31