Thin films of InxGa1-xAs are observed to develop either islands or pits on the surface to relieve lattice mismatch strain after some critical thickness depending on the composition of the film. The composition is thought to alter either the surface energy or the equilibrium adatom concentration of the growing film, thus changing which strain relieving features, islands, or pits nucleate on the surface first. Once pits form, their behavior is similar to that of islanding, resulting in an "inverse" Stranski-Krastanov growth mode. Furthermore, the atomic surface structure near the pits is different than away from the pits and is correlated with island formation. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3474982]