Instability-driven SiGe island growth

Three-dimensional islanding is generally assumed to proceed through nucleat ion and growth. Here we present studies showing the growth of Si1-xGex isla nds (0.2 < x < 0.6) without nucleation. Rather, a strain-driven growth inst ability induces a network of elevated cells, where the angle of elevation s elf-limits when {105} facets form pyramidal islands. These strain-modulated surfaces may serve as a template for the spatially controlled growth of qu antum dot ensembles.