Island nucleation and growth during homoepitaxy on GaAs(0 0 1)-(2×4)

Abstract

Island nucleation and growth during the initial stages of homoepitaxy on GaAs(0 0 1) are studied with atomic-resolution scanning tunneling microscopy (STM) and kinetic Monte Carlo (KMC) simulations that include the zincblende structure of GaAs, the (2×4) reconstruction of the (0 0 1) surface, and the kinetics of As 2 incorporation. By making systematic comparisons between island morphologies measured by STM and those obtained from KMC simulations, we find that the (2×4) reconstruction causes small islands to be unstable until they adopt the local (2×4) structure and we propose a mechanism by which islands evolve toward this structure.