Global faceting behavior of strained Ge islands on Si.

The evolution of crystallographic facets of strained heteroepitaxial Ge islands on Si is investigated. Islands growing on Si(001), (111), (110) and (113) are bound by an equilibrium set of facets that includes only shared stable surfaces between bulk Si and Ge--{105}, {113}, {15 3 23} and {111}. The formation of a stereographic map from these indices facilitates the prediction of Ge faceted-island shapes on any Si substrate at different stages of growth. The analysis presented here can be applied to other heteroepitaxial islanding systems where a finite set of shared equilibrium facets exists for the bulk starting materials.