Internally consistent verification of mean-field models for aggregation using large-scale molecular dynamics

Authors: Manish Prasad, Talid Sinno
Publication Date: February 4, 2004
Journal: Molecular Physics

CitationT. Sinno and M. Prasad, Internally Consistent Verification of Mean-Field Models of Aggregation using Large-Scale Molecular Dynamics, Molecular Physics, 102 (2004) 395-403.

Abstract: The underlying atomistic mechanisms that govern vacancy aggregation in crystalline silicon are probed using a parametrically consistent, two-scale approach. The essential ingredient in this framework is a direct, quantitative comparison between the predictions of atomistic and continuum simulations for the transient size distribution of vacancy clusters. The former is carried out with parallel molecular dynamics simulation of a silicon system containing 215 000 atoms and 1000 vacancies. The continuum model is based on a sequence of coupled Master equations and is parametrized based on the same empirical potential used to perform the atomistic aggregation simulation. An excellent representation of the cluster size distribution can be obtained with consistent parameters only if the relevant physical mechanisms are captured correctly. The inclusion of vacancy cluster diffusion and a model to capture the dynamic nature of cluster morphology at high temperature are necessary to reproduce the results of the large-scale atomistic simulation. Finally, the continuum model is used to investigate cluster evolution for longer times, which are relevant for process simulation of defect-optimized silicon substrates for microelectronic device fabrication.