Berlin 2005 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 25: Si / Ge

HL 25.6: Vortrag

Samstag, 5. März 2005, 12:00–12:15, TU P-N226

X-ray Raman scattering at the Si L-edge of Si and amorphous SiO — •M. Volmer¹, C. Sternemann¹, J.A. Soininen², A. Hohl³, G. Venko⁴, S. Streit¹, and M. Tolan¹ — ¹Institut für Physik, Universität Dortmund, Deutschland — ²Div. X-ray Physics, Dept. Physical Sciences, University of Helsinki, Finland — ³Institute of Materials Science, Darmstadt University of Technology, Germany — ⁴ESRF, Grenoble, France

We present measurements of the Si L-edge of polycrystalline Si and amorphous SiO using the x-ray Raman scattering technique (XRS). The momentum transfer dependence of XRS gives acces to additional monopole excitation channels for the high momentum transfer regime, where the dipole approximation is no longer valid. The Si L-edge spectra show clear momentum transfer dependence with respect to their total shape and will be compared to calculations using a Bethe-Salpeter equation-based approach including core-hole and lifetime effects. The Si L-edge of amorphous SiO exhibits distinct fine structure along with pronounced momentum-transfer dependence. These spectra will be discussed in terms of the interface-clusters mixture model for the structure of amorphous SiO on the basis of a disproportionation of SiO into Si and SiO₂.