Initial stages of epitaxial growth: Gallium arsenide on silicon

Abstract

A model for the morphology of the first layers of GaAs on Si(111) is proposed based on observations of gallium cluster formation on As-terminated Si(111). In this model Ga is mobile and tends to form clusters, but is immobilized by arriving As atoms. Substrate-temperature-dependent ion scattering and transmission electron microscopy investigations are in agreement with this model and allow the extraction of a clustering related activation energy. These results establish conditions necessary for uniform film growth of GaAs/Si at the important film/substrate interface.