ANISOTROPIC SURFACE-DIFFUSION AT CRYSTAL FACET TRANSITIONS DURING LOCALIZED GA-IN-AS-P GROWTH BY MOMBE

Localized grown InP/GaInAs(P) heterostructure ridges by selective area metalorganic molecular beam epitaxy (MOMBE) are investigated concerni ng the surface diffusion. The structures have different crystal facets at the semiconductor mask transition area. The surface diffusion proc esses between these simultaneously growing facets are a function of th e step density, which is preset by the selected substrate misorientati ons. The anisotropic surface diffusion in the direction of the group V terminated surface steps determines the lateral facet growth and lead s to a fine oscillating surface corrugation on the ridge surface only near the step upwards oriented facet transition. A simulation of this anisotropic surface corrugation by a deterministic nonlinear partial d ifferential equation of a one dimensional diffusion model for the sele ctive area growth in MOMBE presents a good agreement with the measured corrugation depth and periods. (C) 1997 Elsevier Science Ltd.