Strained SiGe islands on Si(001): Evolution, motion, dissolution, and plastic relaxation

We report on the morphological evolution of strained SiGe islands epitaxially grown on Si(001). After reviewing the morphological transitions undergone by the islands as their size changes, we present recent results obtained by an approach consisting of “reading the footprints” left by the islands on the Si substrate during growth. Such footprints, which we investigate by a combination of scanning probe microscopy and selective wet chemical etching, are trenches carved in the Si substrate. The study of these trenches allows us to discuss general phenomena occurring during growth or post-growth annealing, such as coarsening and morphological transitions, surface-mediated material intermixing and lateral island motion, evolution of plastically relaxed islands and effect on the islands surrounding them. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)