The formation mechanism of planar defects in compound semiconductors grown epitaxially on {100} silicon substrates

Films of three compound semiconductors with the zincblende structure grown epitaxially on {100} silicon substrates by chemical vapor deposition or metal-organic chemical vapor deposition were investigated by transmission electron microscopy. The three systems have similar thermal mismatches but cover a wide range of lattice mismatch. From the comparison of the observed microstructures as well as from the investigation of early stages of film formation it is concluded that the lattice mismatch plays a minor role in the formation of stacking faults and twin boundaries. A formation mechanism is proposed for these defects which is based on deposition errors during the adsorption of atoms on {111} facets of film nuclei. The observed microstructural features are discussed in terms of this model.