Hugh-like island growth of Ge on strained vicinal Si(111) surfaces

We examine the structure and the evolution of Ge islands epitaxially grown on vicinal Si(111) 6 surfaces by scanning tunneling microscopy. Contrary to what is observed on the singular surface, 7 three-dimensional Ge nanoislands form directly through the elastic relaxation of step-edge 8 protrusions during the unstable step-flow growth. As the substrate misorientation is increased, the 9 islands undergo a shape transformation which is driven by surface energy minimization and 10 controlled by the miscut angle. Using finite element simulations, we show that the dynamics of 11 islanding observed in the experiment results from the anisotropy of the strain relaxation. VC 2011 12 American Institute of Physics. [doi:10.1063/1.3655906