Anisotropic surface diffusion at crystal facet transitions during localized GaInAsP growth by MOMBE

Abstract

Localized grown InP/GaInAs(P) heterostructure ridges by selective area metalorganic molecular beam epitaxy (MOMBE) are investigated concerning the surface diffusion. The structures have different crystal facets at the semiconductor mask transition area. The surface diffusion processes between these simultaneously growing facets are a function of the step density, which is preset by the selected substrate misorientations. The anisotropic surface diffusion in the direction of the group V terminated surface steps determines the lateral facet growth and leads 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 differential equation of a one dimensional diffusion model for the selective area growth in MOMBE presents a good agreement with the measured corrugation depth and periods.