Structural transformations from point to extended defects in silicon: A molecular dynamics study

Abstract

We use classical molecular dynamics simulation techniques to study how point defects aggregate to form extended defects in silicon. We have found that $⟨110⟩$ chains of alternating interstitials and bond defects, a generalization of the Si di-interstitial structure, are metastable at room temperature but spontaneously transform into {311} defects when annealed at higher temperatures. Obtained atomic configurations and energetics are in good agreement with experiments and previous theoretical calculations. We have found a {311} structural unit which consists of two interstitial chains along $⟨110⟩$ but arranged differently with respect to the known {311} units.