Two-dimensional dynamical model for step bunching and pattern formation induced by surface reconstruction

Abstract

Surface reconstruction on sufficiently wide terraces on a vicinal surface can cause the formation of step bunches. We consider this process in the nucleation regime using a two-dimensional (2D) dynamical model that describes both surface reconstruction and the effects of the growth of a reconstructed facet on the motion of neighboring steps. When there is local mass transport, we show that the growth of a reconstructed facet can induce the growth of a similar facet nearby, leading to regular arrangements of flat facets separated by step bunches and to other characteristic 2D step patterns.