Elastic strain relaxation in discontinuous wetting layers and its impact on lateral ordering of heteroepitaxial dots

Abstract

We discuss morphological changes of strained $\mathrm{Si}\mathrm{Ge}∕\mathrm{Si}(001)$ dots grown from an indium solution. In the course of a particular depletion scenario initial, lenslike dots transform into truncated pyramids of fourfold symmetry inside circular rims of rising height and steep inner edge. Further dot nucleation performs close to the rim indicating elastically relaxed lattice sites. The observations made are supported by numerical finite element calculations on the strain energy distribution.