Published online by Cambridge University Press: 28 February 2011
Reflection high energy electron diffraction (RHEED) measurements indicate that the adsorption of As on misoriented Si(100) surfaces drives a multilayer step transition. We find that the formation of multilayer steps is a strong function of substrate temperature and As pressure. Monolayer steps are metastable at low substrate temperature or As pressure. The subsequent nucleation and growth of GaAs by molecular beam epitaxy (MBE) is controlled by the initial Si step distribution. Single domain GaAs grown on the monolayer stepped substrate has Ga terminated steps. Conversely, single domain GaAs grown on the multilayer stepped substrate has As terminated steps.