Simulation model for self-ordering of strained islands in molecular-beam epitaxy

The growth of quasiordered ultrasmall InAs islands by molecular-beam epitaxy utilizing the intrinsic elastic strain between the islands and the substrate is a promising approach to fabricate regular arrays of defect-free quantum dots. In this paper, a simulation of the island growth kinetics based on a phenomenological approach that introduces an effective exclusion zone that mimics the strain effects surrounding a growing island is described. The simulation results, in qualitative agreement with experiments, show that the growth kinetics can induce a quasiordering in the island position if either the exclusion zone or the nuclei density is sufficiently large.