The evolution of strained Ge/Si(111) Stranski-Krastanov islands was monitored by means of atomic force and scanning tunnelling microscopy. By following morphological changes during annealing, it was possible to recognize the key features of relaxation in these structures. The introduction of edge misfit dislocations above a critical thickness, and an inhomogeneous strain field within the islands, led to intra-island ripening. It was shown that this mechanism changed the island shape from a truncated tetrahedron to atoll-like.

Evolution of Strained Ge Islands Grown on Si(111) - a Scanning Probe Microscopy Study G.Capellini, N.Motta, A.Sgarlata, R.Calarco: Solid State Communications, 1999, 112[3], 145-9