Surface electromigration of In-covered Si high-index surfaces

To clarify the role of facet in electromigration on the vicinal Si(0 0 1), we investigated in this study surface mass transport of In on Si high-index (1 0 3) and vicinal (0 0 1) surfaces, using scanning Auger microscope, low energy electron diffraction (LEED) and atomic force microscope (AFM). In parallel with (1 0 3), we also investigated similarly the most stable high-index (1 1 3) of Si for reference. Specimens with a large area of these surfaces were prepared from Si(0 0 1) wafer by cutting, grinding and polishing. No surface electromigration of In on Si(1 0 3) surface was observed at any temperature, while In overlayer exhibited a typical Stranski-Krastanov mode of growth. This fact strongly suggests that In adatoms move around over the intermediate layer, but there is no driving force of electromigration on them. The electromigration on the vicinal Si(0 0 1) depended upon the off-angle. It was most enhanced with the off-angle of around 4 deg. . Based upon these results a model is proposed to explain the puzzling electromigration of In on vicinal Si(0 0 1). We found out that In on Si(1 1 3) exhibited a normal surface electromigration towards cathode