The epitaxial growth of compound semiconductors observed by atomic force microscopy

Results will be reported on atomic force microscopy (AFM) of features of homoepitaxial growth of GaAs, InP, and strained layer growth of Ga1-xInxAs on GaAs by metalorganic vapour phase epitaxy (MOVPE) and homoepitaxial growth of GaAs by molecular beam epitaxy (MBE). Growth was found to be by the classical step-flow mode. Defects were seen to act as strong persistent step sources. We observed spiral growth originating at screw dislocations and ring-pattern growth, probably originating at the intersection of stacking faults with the surface. The same features were seen for MBE growth of GaAs but step growth was irregular in particular directions due to surface reconstruction. In the case of strained layer growth we observed the transition from two to three dimensional growth and the generation of misfit dislocations.