Berlin 2008 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 54: Si/Ge
HL 54.8: Vortrag
Freitag, 29. Februar 2008, 12:15–12:30, EW 202
Oxidation and graphitization of 6H-SiC (0001) — Maxim Eremtchenko1, Anita Neumann1, Jens Uhlig1, Rolf Öttking1, Roland J. Koch1, Katharina Kloeckner1, Thomas Haensel1, Syed Imad-Uddin Ahmed1, and •Juergen A. Schaefer1,2 — 1Institut für Physik and Institut für Mikro- und Nanotechnologien, TU Ilmenau, P.O. Box 100565, 98684 Ilmenau, Germany — 2Department of Physics, Montana State University, P.O. Box 173840, Bozeman, MT 59717-3840, USA
The silicon rich 6H-SiC (0001) surface, its oxidation, graphitization and possible graphene layer formation has been investigated using high resolution electron energy loss spectroscopy in combination with X-ray induced photoelectron spectroscopy and low energy electron diffraction. Annealing up to 1000∘C resulted in SiO2 formation, while graphitization and finally the build up of graphitic clusters followed annealing up to 1170∘C. Characteristic changes in surface cleanliness, stoichiometry (Si-rich to C-rich) and different surface structures induced drastically different depletion layers with different band bendings as a function of isochronal annealing temperatures. A key feature of this work is that the semimetallic character of graphite and/or graphene formation of intentionally low doped (2.5 x 1015 cm−3 n-type) SiC (0001) material could be precisely monitored by analyzing the continuous background of inelastically reflected electrons in HREELS-experiments. This result is very promising for future studies related to the identification of the presence and morphology of graphene layer formation on top of silicon carbide, and to its electronic as well as vibrational structure.