Vacancy diffusion in silicon was investigated using kinetic lattice Monte Carlo simulations of temperatures below the melting point. Equilibrium diffusivities in the cluster region were two orders of magnitude lower than those of free vacancies, which were deduced from a known low density system. While the mean cluster size was almost constant below 1200K, it increased at 1300 to 1400K and then decreased after the peak temperature of 1400K was reached. The number of clusters increased slightly from 800 to 1200K whereas it decreased abruptly above 1300K. While high temperatures resulted in fewer large vacancy clusters, many small clusters at low temperatures resulted in fewer free vacancies in intermediate phases between aggregation and dissociation of smaller clusters. The effective migration energies of a silicon vacancy below the melting point were 2.5 and 0.47eV at above and below 1300K, respectively.

Kinetic Lattice Monte Carlo Simulations of Vacancy Diffusion in Silicon Below the Melting Point. J.W.Kang, O.K.Kwon, S.Lee, S.H.Lee, D.H.Kim, H.J.Hwang: Journal of Computational and Theoretical Nanoscience, 2010, 7[3], 604-11