Growth of epitaxial Bi-films on vicinal Si(111)

Vicinal semi-metallic Bi-films are expected to reveal topologically protected edge states. In this study the growth of Bi-multilayer structures on Si(557) substrates has been investigated by low energy electron diffraction. Thereby, wetting layer structures formed prior to the film deposition on Si(557) surfaces turned out to be crucial for epitaxial growth. Only in the presence of Bi-wetting layers can well-ordered films be grown. In contrast to growth on Si(111), the pseudo-cubic surface of Bi(110) dominates. In addition, Bi(221) surfaces have been obtained only on wetting layers formed by less than a monolayer. The formation of Si(335)-facets during formation of the wetting layers turns out to be essential for the growth of the these structures.