A computational method was described for investigating the nucleation and growth of vacancy clusters in crystalline Si. The approach was based upon a parametrically consistent comparison between 2 representations of the process. This provided a systematic method for probing the details of the atomic mechanisms responsible for aggregation. A detailed set of targeted atomistic simulations was first described which fully characterized the thermodynamic and transport properties of vacancy clusters with a wide range of sizes. It was shown that cluster diffusion was surprisingly favorable, due to the availability of multiple - and almost degenerate - configurations. A single large-scale parallel molecular dynamics simulation was then used to model directly the evolution of the vacancy cluster-size distribution in a supersaturated state which initially involved 1000 uniformly distributed vacancies in a host lattice of 216000 Si atoms at 1600K. The results of the simulation were interpreted in terms of the observed power-law evolution of the size-distribution moments. It was shown that the molecular dynamics results for the aggregation of vacancy clusters, and especially the evolution of the average cluster size, could be well-represented by using a much-simplified mean-field model.

Internally Consistent Approach for Modelling Solid-State Aggregation I - Atomistic Calculations of Vacancy Clustering in Silicon. M.Prasad, T.Sinno: Physical Review B, 2003, 68[4], 045206 (12pp)