Electronic structure of the laser-annealed Si(111)1 × 1 surface

• Published in: Surface science 1995-04, Vol.327 (3), p.233-240
• Main Authors: Öfner, H., Ulrych, I., Chab, V., Netzer, F.P., Matthew, J.A.D.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Electron energy loss spectroscopy; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Inverse photoemission spectroscopy; Laser annealing; Low index single crystal surfaces; Physics; Semiconducting surfaces; Silicon; Solid surfaces and solid-solid interfaces; Surface and interface electron states; Surface states, band structure, electron density of states; Surface structure, morphology, roughness, and topography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(94)00853-1

Clean Si(111)1 × 1 surfaces have been prepared by Nd:YAG laser annealing of Si(111)7 × 7 surfaces, and the changes of the electronic structure during the (7 × 7) → (1 × 1) transition have been monitored by inverse photoemission spectroscopy (IPES) and electron energy loss spectroscopy (EELS). The laser energy densities necessary to generate the (1 × 1) structure have been varied to detect the “damage threshold”, i.e. the amorphisation of the surface, from the IPES spectra. The surface state peaks in the IPES spectra occur at similar energies on the (7 × 7) and the (1 × 1) surfaces, but their angular intensity distributions are different. The surface plasmon energy in EELS is shifted by 0.6 eV to higher loss energy on the (1 × 1) surface as compared to the one at the (7 × 7) surface. A simple model using an effective dielectric function of the surface layer gives qualitative insight into the observed surface plasmon behaviour.