Influence of rough substrates on the morphology evolution of epitaxial films

We present results of Monte Carlo simulation of the morphology evolution of films grown on rough substrates. The initial surfaces considered for the simulation are similar to those of substrates used for the growth of GaAs films by chemical and molecular beam epitaxy. When the growth is simulated in the absence of the Erhlich-Schwoebel effect, decreasing film roughness is observed until a stable value is reached. During this decrease we observe the formation of moundlike structures of a few monolayers in height. In some conditions the structures forming the initial rough surface (pits) present a limitation to the lateral size of these mounds. These simulation results are in qualitative agreement with experimental results for homoepitaxial GaAs films grown by chemical beam epitaxy.