Unusual Surface Undulations Observed in Ge/Si(100) Multilayers

Abstract

AbstractMultilayer Ge/Si quantum wells grown on Si(100) at lower temperatures (300 C for Ge and 435 C for Si) exhibit unexpected large surface undulations. These groove-like features along <110> directions are correlated to the underlying dislocation networks. Studies on the dependence of surface roughness versus Ge spacer thickness exclude kinetic limitation as the cause of the observed troughs. Further comparison of the surfaces for multilayer and single-layer samples indicates a combination of the multilayer structure and the inhomogeneous surface strain field greatly enhances the undulations.