An investigation was made of the surface kinetics during metalorganic vapor-phase epitaxy, using high-vacuum scanning tunneling microscopic observations of 2D nuclei and denuded zones, using Monte Carlo simulations based upon the solid-on-solid model. From 2D nucleus densities, the surface diffusion coefficients of GaAs and AlAs were estimated to be 2 x 10-6 and 1.5 x 10-7cm2/s at 530C, and the energy barriers to migration were 0.62 and 0.8eV, respectively. The 2D nucleus size in the [110] direction was about two times larger than that in the [1¯10] direction. The size anisotropy was caused mainly by a difference in the lateral sticking probability (Ps) between steps along the [1¯10] direction (A steps) and steps along the [110] direction (B steps). The Ps ratio was estimated to be greater than 3:1. Denuded zone-widths on upper terraces were 2 times wider than those on lower terraces. This showed that Ps at descending steps was 10 to 300 times larger than Ps at ascending steps.

Surface Diffusion Kinetics of GaAs and AlAs Metalorganic Vapor-Phase Epitaxy. M.Kasu, N.Kobayashi: Journal of Crystal Growth, 1997, 170[1-4], 246-50