Dresden 2006 – scientific programme

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DS: Dünne Schichten

DS 18: Thin semiconducting films

DS 18.5: Invited Talk

Thursday, March 30, 2006, 10:30–11:15, GER 38

Formation and Decay of Si/Ge Nanostructures at the Atomic Level — •Bert Voigtländer — Institut für Schichten und Grenzflächen ISG 3 and cni - Center of Nanoelectronic Systems for Information Technology, Forschungszentrum Jülich, 52425 Jülich, Germany

The step-flow growth mode is used to fabricate two-dimensional Si and Ge nanowires with a width of 3.5 nm and a thickness of one atomic layer (0.3 nm) by self-assembly on a Si(111) surface. Alternating deposition of Ge and Si results in the formation of a nanowire superlattice covering the whole surface. One atomic layer of Bi terminating the surface is used to distinguish between the elements Si and Ge. A difference in apparent height is measured in scanning tunneling microscopy (STM) images for Si and Ge, respectively. The reason for the height difference observed in STM will be discussed. Also different kinds of two-dimensional Si/Ge nanostructures like alternating Si and Ge nanorings having a width of 5-10 nm were grown. The method to distinguish between Si and Ge allows to study intermixing on the nanoscale and to identify the fundamental diffusion processes giving rise to the intermixing.