Surface-state band structure of the Si(100)2×1 surface studied with polarization-dependent angle-resolved photoemission on single-domain surfaces

The electronic structure of the Si(100)2×1 surface has been studied with polarization-dependent angle-resolved photoemission. By using vicinal Si(100) samples, single-domain 2×1 surfaces were obtained, and the surface-band dispersions were measured unambiguously along the symmetry axes Γ¯-J¯’ and Γ¯-J¯ in the surface Brillouin zone (SBZ). The obtained dispersions are compared to dispersions from earlier studies of two-domain surfaces, as well as to theoretical band-structure calculations. In addition to the well-known surface state attributed to the dangling bonds, five more surface-related structures were observed on the single-domain surface. One of these is the controversial surface state previously observed on two-domain surfaces at J¯’ in the [010] direction at ∼0.9 eV below the Fermi level (${\mathit{E}}_{\mathit{F}}$), which is not accounted for in any calculated surface band structure for the Si(100)2×1 surface. Contrary to a previous report, it is also observed on the single-domain surface at several points in the SBZ.