Selective positioning of InAs self-organized quantum dots on sub-250 nm GaAs facets

Abstract
We have selectively grown GaAs mesas with (100) top facets that range from several μm to less than 250 nm in width on an oxide-patterned GaAs substrate, and InAs self-organized quantum dots (SOQDs) on top of the facets. For a given amount of InAs deposited, the dot density varies with the facet width, and is higher than the density on a planar, nonpatterned substrate. The SOQDs also tend to form at the facet edges. These observations are indicative of a strong surface diffusion effect of In-containing species adsorbed on the various crystalline facets of the GaAs mesas.