Dresden 2006 – scientific programme

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MM: Metall- und Materialphysik

MM 29: Poster Session (SYNW)

MM 29.1: Poster

Thursday, March 30, 2006, 10:00–11:00, P4

Contacting low dimensional metallic nanostructures on silicon — •Jan Rönspies¹, Svend Vagt¹, Tammo Block¹, Volkmar Zielasek², and Herbert Pfnür¹ — ¹Institut für Festkörperphysik, Abteilung Oberflächen, Universität Hannover, Appelstr.2, 30167 Hannover, Germany — ²Institut für Angewandte und Physikalische Chemie, Universität Bremen, 28359 Bremen, Germnay

The reliable fabrication of electrical contacts to conducting nanostructures is still a challenging problem to be solved. In our experiment we produced nanowires by a lithographic process with electron-beam stimulated thermal desorption of oxygen (EBSTD) in UHV from an ultrathin SiO₂ layer deposited on Si(557) and Si(111) substrates. We formed nanowires with a diameter of 10nm and a length of several hundred nanometers with Pb/Si(557) and Ag/Si(111) as example of 1D and 2D systems. For electrical contacting these nanostructures, an ex-situ electron beam lithographic process was used to create TiSi₂ macro-contacts forming a gap of a few hundred nanometers. The contacts were evaporated as a multi-layer system of Si followed by a Ti-layer and a capping of Si on a Si(557) substrate to avoid stress induced trenches at the transition between the contacts and the substrate. We studied these contacts by SEM, STM, and Auger analysis, and found that they are stable up to 1200K, UHV compatible and exhibit metallic conductance. Further analysis focusses on this transition from the macroscopic to the mesoscopic structures.