We present results of Monte Carlo simulation of the morphology evolution of
films grown on rough substrates. The initial surfaces considered for the s
imulation are similar to those of substrates used for the growth of GaAs fi
lms 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 t
he 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 G
aAs films grown by chemical beam epitaxy.