Defect-induced homogeneous amorphization of silicon: the role of defect structure andpopulation

Abstract

Molecular dynamics based on the environment-dependent interatomic potential is used toinvestigate the influence of the nature and distribution of defects on solid state,homogeneous amorphization of Si. To this end, different kinds of defects, including singleinterstitials and vacancies (both uncorrelated and correlated distributions), bonddefects, and small interstitial and vacancy clusters, have been considered. It isshown that the threshold defect concentration for amorphization depends on thedefect type, and, in the case of single defects, on the degree of correlation betweeninterstitial and vacancy distributions. The threshold varies within the interval[0.18–0.28] atomic fraction, the upper value corresponding to the case of bonddefects, the lower to the uncorrelated distributions of single split interstitials plus compensating vacancies.