Ge cluster formation with monolayer and submonolayer coverages on the GaAs(110) surface

Abstract

We examine the deposition process of Ge adatoms on the GaAs(110) surface. We use total energy calculations based on ab initio pseudopotentials constructed within the local density approximation. The equilibrium morpholoies for the adatoms, and the growth pattern determined for monolayer and submonolayer coverages, are calculated. Also, the binding energy of different sites, vibrational frequencies of adatoms on these sites, and the migration energy barrier along the [11̄0] direction are presented. Our theoretical model for Ge cluster formation and morphology on the GaAs surface is consistent with recent scanning tunnelling microscopy measurements for this surface.