Regensburg 2007 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 20: Symposium: Real Time Growth Studies I
DS 20.3: Vortrag
Donnerstag, 29. März 2007, 10:00–10:15, H32
Layer-by-layer growth of thin epitaxial iron silicide films on GaAs — •Bernd Jenichen, Vladimir Kaganer, Wolfgang Braun, Jens Herfort, Roman Shayduk, Claudia Herrmann, and Klaus Ploog — Paul-Drude-Institut, Hausvogteiplatz 5-7, 10117 Berlin
The layer-by-layer growth mode during molecular beam epitaxy allows the controlled fabrication of epitaxial layer sequences with very sharp interfaces between them. The aim of the present work is the in-situ characterization of the Fe3Si epitaxial growth process in the layer-by-layer growth mode by x-ray surface diffraction methods in order to achieve high-quality interfaces. The long range ordering in the films is monitored by measuring different Fe3Si superlattice reflections. The Fe3Si layers were grown under x-ray control on the As-rich GaAs surface at different substrate temperatures near 200∘C which is the optimum growth temperature with respect to structural and interfacial perfection and a high degree of long range atomic order. The Si and the Fe cell temperatures were tuned in order to achieve perfect lattice match of the Fe3Si to the GaAs substrate and at the same time full stoichiometry of the films. An anneal of the surface at 310∘ C for about 1 h together with the growth of one ML of Fe3Si improved the surface quality considerably, which is determined in situ by the increasing intensity of the x-ray surface reflections. X-ray intensity oscillations were obtained after such an annealing procedure. Fe3Si grows indeed layer-by-layer. The measured curves exhibit damping, indicating that several terrace levels contribute to the diffracted intensity.