Complex dynamical phenomena in heavily arsenic doped silicon

Several complex dynamical phenomena have been observed in heavily doped Si, but a comprehensive account of the underlying atomic-scale processes is lacking. We report a wide array of first-principles calculations in terms of which we give such a comprehensive account. In particular, we find that vacancies (V), AsV pairs, As2V complexes, and higher-order AsnVm complexes play distinct roles in the observed dopant deactivation, reactivation, and anomalous diffusion. The latter is mediated by mobile As2V complexes that form in ''prepercolation'' patches of a very high dopant concentrations and gives rise to fast As clustering at moderate temperatures. Our results are quantitative and in agreement with experimental numbers where available.