Carbon-mediated aggregation of self-interstitials in silicon: A large-scale molecular dynamics study

Abstract

The carbon-mediated aggregation of silicon self-interstitials is investigated with large-scale parallel molecular dynamics. The presence of carbon in the silicon matrix is shown to lead to concentration-dependent self-interstitial cluster pinning, dramatically reducing cluster coalescence and thereby inhibiting the nucleation process. The extent of cluster pinning increases with cluster size for the range of cluster sizes observed in the simulation. The direct effect of carbon on single self-interstitials is shown to be of secondary importance, and the concentration of single self-interstitials as a function of time is essentially unchanged in the presence of carbon. A quasi-single-component mean-field interpretation of the atomistic simulation results is proposed and further confirms these conclusions. Based on these results, it is suggested that the experimentally observed effect of carbon on transient-enhanced diffusion of boron could be due to the direct interaction between carbon atoms and self-interstitial clusters.