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DS: Fachverband Dünne Schichten
DS 11: Layer Growth: Evolution of Structure and Simulation
DS 11.1: Talk
Tuesday, March 24, 2009, 14:00–14:15, GER 37
Material dependent smoothing of rippled surfaces — •Johanna Röder and Hans-Ulrich Krebs — Institut für Materialphysik, Universität Göttingen, Friedrich-Hund-Platz 1, D-37077 Göttingen, Germany
Any kind of processing of materials like thin film deposition, ion beam treatment or polishing often creates structures, which have lateral length scales of 20-200 nm. For many applications, like optical mirrors or thin multilayer structures, it is important to avoid roughnesses in these dimensions. Up to now a lot of experimental and theoretical work has been done to investigate the roughness evolution during film growth on a smooth substrate. Another approach is the investigation of the growth of films deposited on already rough surfaces, where smoothing mechanisms influence the evolution of the surface and can be analysed more easily. In this contribution, the successive smoothing of artificially created rough surfaces has been studied by atomic force microscopy. Therefore periodic structured Si(100) surfaces (height of 4,5nm, period of 55nm) produced by sputter erosion were chosen as model system and systematically covered by thin layers of different material classes like oxides (ZrO2), simple carbides (C) and polymers (PC). The results were discussed with respect to the dominating smoothing mechanisms that occur during deposition. The scaling behaviour of the roughness evolution was investigated in Fourier space using power spectral densities (PSD). The three material classes will be compared and the differences during the smoothing process discussed. All samples were deposited by pulsed laser deposition.