Topography of high- and low-index GaAs surfaces

Abstract

We have investigated the surface structure of the nonsingular (331), (311), (211), and (210) GaAs surfaces and of the singular (110) and (111) GaAs surfaces during molecular-beam epitaxy. Reflection high-energy electron diffraction directly reveals the formation of periodically arranged macrosteps with spacings and heights in the nanometer range. Nonsingular planes break up into singular surface configurations, whereas the singular surfaces transform into vicinal planes. Surface reconstruction plays an important role in the stabilization of terrace and step widths. The surface structures give rise to lateral confinement effects, which drastically changes the electronic properties of GaAs/AlAs multilayer structures.