Atomistic simulation of point defects in silicon at high temperature

Abstract

The Stillinger–Weber interatomic potential is used in molecular dynamics simulations to compute estimates of the equilibrium and transport properties of self-interstitials and vacancies in crystalline silicon at high temperature. Equilibrium configurations are predicted as a 〈110〉 dumbbell for a self-interstitial, and as an inwardly relaxed configuration for a vacancy. Both structures show considerable delocalization with increasing temperature, which leads to a strong temperature dependence of the entropy of formation, as suggested by diffusion experiments. Diffusion coefficients and mechanisms are predicted as a function of temperature. The predictions are discussed in the context of experiments and first-principle calculations.