Au island growth on a Si(111) vicinal surface

Au island nucleation and growth on a Si(111) 7 · 7 vicinal surface was studied by means of scanning tunneling microscopy. The surfacewas prepared to have a regular array of step bunches. Growth temperature and Au coverage were varied in the 255–430 C substratetemperature range and from 1 to 7 monolayers, respectively. Two kinds of islands are observed on the surface: Au–Si reconstructedislands on the terraces and three-dimensional (3D) islands along the step bunches. Focusing on the latter, the dependence of island density,size and position on substrate temperature and on Au coverage is investigated. At 340 C and above, hemispherical 3D islandsnucleate systematically on the step edges.