Decay of an Island on a Facet via Surface Diffusion

Abstract

We study the decay process of a small island formed on a facet by numerical integration of a simple model and by theoretical analysis. The relaxation proceeds via surface diffusion without evaporation and impingement of atoms. Steps on the top of the island shrink due to the step tension and a small facet appears. The size of the facet increases as the power of time R_f-- t^ν, where the exponent ν depends on the initial shape and the rate limiting process. In the kinetics-limited case, step bunching occurs from the bottom and the enlargement of the facet stops at some stage. Analytical expressions for the bunch velocity and the island profile are found.