On the possibility of two-dimensional growth of GaAs on atomically flat Si(100) surfaces

The possibility of growing GaAs on atomically flat Si(100) surfaces is investigated at monolayer and bilayer coverages. Based on ab-initio total-energy calculations at zero-temperature we compare the stability of separate domains of Ga or As versus mixed monolayers, the stability of pure GaAs bilayers versus mixed bilayers and the formation of GaAs bilayer islands versus wetting of the surface. The results predict that two-dimensional growth of bulk GaAs on atomically flat regions (terraces) of Si(100) is severely inhibited at the initial stages, due to chemical and rehybridization reactions of the Ga and As atoms on the Si surface. © 1989.