Strained InAs nanostructures self-organised on high-index InP 113/B

We investigated self-assembled InAs islands grown on In0.52 Al0.48AsrInP 113.B by molecular beam epitaxy MBE. using in-situ reflection high-energy electron diffraction RHEED.and in-situ scanning tunnelling microscopy STM.. For a deposition of 3 monolayers MLs.of InAs, the STM topography revealed a high density of well-organised hexagonal facetted dots. The dots are truncated height ;3 nm.and elongated along thew1 1 0xdirection. Their typical base dimensions are approximately 48 and 19 nm. The angles between facet orientation and crystal direction were accurately deduced from RHEED patterns. From these structural characterisations, the dot shape and formation mechanism are discussed using a standard scheme based on surface energy minimisation. A direct correlation is found between the dot shape and the surface reconstruction unit cell. q2000 Elsevier Science B.V. All rights reserved