A systematic study, using density functional theory (within the local density approximation), was made of the effect of composition on the self-diffusion of Si in Si–Ge alloys diffusing by a vacancy mechanism. The composition dependence of the vacancy formation energy was calculated. A data-base of ab initio migration energy barriers for vacancy migration in different local environments was systematically developed by considering the effect of the first nearest neighbor sites explicitly and the effect of the other sites by a mean field approximation. A kinetic Monte Carlo simulation based upon the migration energy barrier database was used to determine the dependence (upon composition) of the activation energy for the diffusion of Si in Si1–xGex. A detailed study of the variation of the correlation factor with composition and temperature in Si1–xGex was performed using the results of the kinetic Monte Carlo simulation.

Effect of Composition on Vacancy Mediated Diffusion in Random Binary Alloys - First Principles Study of the Si1–xGex System. P.Ramanarayanan, K.Cho, B.M.Clemens: Journal of Applied Physics, 2003, 94[1], 174-85