SCANNING-TUNNELING-MICROSCOPY STUDY OF THE EPITAXIAL-GROWTH OF STRAINED IN0.82GA0.18AS LAYERS ON INP

The 2D-3D growth mode transition of compressively strained InxGa1-xAs layers (x = 0.82 or 2% lattice mismatch) grown on an In0.53Ga0.47As bu ffer layer lattice matched to InP was studied using scanning tunneling microscopy. Up to 4 deposited monolayers, a layer by layer growth mod e is maintained. The surface layer appears to be more compact for the strained layers than for the lattice matched buffer layer, After 5 mon olayers were deposited the surface topography undergoes very significa nt change and threedimensional patterns, highly anisotropic in the gro wing plane, appear. These remarkable evolutions are attributed to the competition between surface energy necessary to form new island facets and elastic energy relaxation allowed with small sized islands.