Critical thickness for pseudomorphic growth of Si/Ge alloys and superlattices

Abstract

A model, based on energy considerations, to determine the critical thickness for pseudomorphic growth of Si/Ge alloys and superlattices is introduced. Comparison with experiments shows a good agreement between the theory and experiment. It is also shown that in films which are initially dislocation-free, the energy barrier for the nucleation of dislocation loops can be crossed by thermal activation if the film is thicker than the critical value provided by the model.