Local self-organization of islands in embedded nanodot systems

We show that strain distribution on the surface of an isotropic spacer layer induced by an embedded island of large base-to-height aspect ratio deviates significantly from the description of the point force dipole model in the regime of small spacer layer thickness. In this regime, the strain profile displays several local maxima above the embedded island. The regions with local strain maxima serve as nucleation centers for growth of surface islands under appropriate growth conditions, resulting in locally well-organized surface islands above the embedded island. Our theoretical results are in excellent agreement with recent experiments for Ge islands embedded in Si. (C) 2004 American Institute of Physics.