Regular distribution of (3×3) Bi-reconstructed stripes on Si(553) surface

The crystallographic and electronic structures of (3×3) Bi-induced reconstructions of Si(553) surface are investigated with reflection high energy electron diffraction (RHEED), scanning tunneling microscopy and angle resolved photoelectron spectroscopy. The α and β (3×3) superstructures have been obtained at 1/3 and 1 monolayer of Bi, respectively. RHEED experiments indicate that α(3×3) is formed on wide (111) terraces separated by (331) facets while the β(3×3) phase stabilizes regular distribution of steps over entire Si(553) surface. In the latter case the double atomic height steps separate Bi-reconstructed (111) terraces of about 3 nm in width. Only one orientation of (3×3) reconstruction is formed as a consequence of broken three-fold symmetry. The electronic structures of both Bi-induced superstructures are similar to the corresponding ones obtained for a flat Si(111) surface.