ROUGHENING AND FACETING IN LATTICE-MISMATCHED HETEROEPITAXIAL GROWTH OF COMPOUND SEMICONDUCTORS - A MONTE-CARLO STUDY

The (100) heteroepitaxial growth of lattice-mismatched semiconductors is simulated by associating the Monte Carlo technique and the valence force field approximation used for the strain energy calculations. It is shown that V-shaped defects showing (111) facets are formed in the early stages of the growth owing to enhanced interlayer migrations and are at the origin of the roughening of the layer. These defects can b e filled later, leaving behind misfit dislocations, or can extend, lea ding to islands with (111) facets, in agreement with experimental obse rvations.