Adsorbate-induced faceting of high-index semiconductor surfaces: antimony adsorbed on Ge 103/

Scanning tunneling microscopy, low-energy electron diffraction and reflection high-energy electron diffraction were used to monitor changes in the morphology of Ge 103. surfaces after adsorption of antimony and annealing at different temperatures for various durations. After deposition of Sb at room temperature, the Sb-covered Ge 103.surface breaks up on annealing into small irregular pyramids, which coalesce and form more regular quasi-one-dimensional ‘hill-and-valley’ structures bounded by reconstructed 1134facets. The average periodicity of the structures approaches a constant maximum value in the nanometer range. The symmetry of the substrate with respect to the facets constrains the formation of single domain nanostructures. q1999 Elsevier Science B.V. All rights reserved.