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DS: Dünne Schichten

DS 22: Optische Spektroskopie dünner Schichten II

DS 22.4: Vortrag

Dienstag, 8. März 2005, 15:15–15:30, TU HS110

New opportunities for RAS analysis of metal surfaces and thin films — •Peter Zeppenfeld, Lidong Sun, and Michael Hohage — Institut für Experimentalphysik, Universität Linz, Austria

During the last decade, reflectance anisotropy spectroscopy (RAS) has proven to be a powerful tool for the analysis of metal surfaces, in addition to its well established application to semiconductor surfaces and thin films. Various issues such as the adsorption and growth, surface restructuring and the morphological changes during ion sputtering or thermal treatment can be conveniently monitored in situ and in real time using the RAS technique. Yet, the electronic structure and the associated optical properties of metal surfaces are quite different from those of semiconductors. This introduces new challenges for the understanding of the origin and the quantification of the RAS signals from metal surfaces, but it also offers new opportunities and applications. For instance, the presence of delocalized (free electron like) surface states on metal surfaces makes RAS an extremely sensitive tool for studying adsorption kinetics and ordering phenomena. On the other hand, bulk derived contributions to the optical anisotropy are sensitive to thin film and surface stress and can thus be used to characterize the growth mode and morphological changes of thin metal films through the associated characteristic strain/stress variations. Finally, we demonstrate that apart from morphological changes, RAS also allows to follow the evolution of the electronic band structure of a growing thin metal film in a layer by layer fashion.