Dresden 2006 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
O: Oberflächenphysik
O 14: Poster session I (Adsorption, Epitaxy and growth, Phase transitions, Surface reactions, Organic films, Electronic structure, Methods) (sponsored by Omicron Nanotechnology GmbH)
O 14.17: Poster
Montag, 27. März 2006, 18:00–21:00, P2
Core level photoelectron spectroscopy studies of Au/4H-SiC (0001) surface — •C. Virojanadara1,2 and L.I. Johansson1 — 1IFM, Linköping University,Linköping, Sweden. — 2Present address: Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
Studies of Au overlayers on two differently prepared SiC(0001) surfaces are reported. A Si-rich 3x3 surface prepared by Si deposition and subsequent annealing and a (√3×√3) R30∘ reconstructed prepared by in situ heating only. The effects induced by Au layers deposited on these surfaces were investigated using photoemission and low energy electron diffraction (LEED). The formation of ordered overlayer structures was identified and features developing in the Si 2p, C 1s and Au 4f core level spectra were investigated in detail. After deposition of 4 to 8 Å thick Au layers on the 3x3 surface three new stable reconstructions 2√3×2√3 R30∘, 3x3 and 5x5 were revealed after annealing at progressively higher temperatures between 500-900∘C. The surface related components appearing in the Si 2p and Au 4f core levels indicated silicide formation. The LEED pattern and the intensity variations observed for the different core level components versus photon energy suggested formation of an ordered Au-silicide with some excess Si on the top. For the (√3×√3) R30∘surface the evolution of the core level spectra after Au deposition and annealing was found to be distinctly different compared to the Si-rich 3x3 surface. Only one stable reconstruction, a 3x3 phase, was then observed at similar annealing temperatures. These findings will be presented and discussed.