Regensburg 2004 – wissenschaftliches Programm

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O: Oberflächenphysik

O 14: Postersitzung (Adsorption an Oberflächen, Epitaxie und Wachstum, Organische Dünnschichten, Oxide und Isolatoren, Phasenübergänge, Rastersondentechniken, Struktur und Dynamik reiner Oberflächen)

O 14.35: Poster

Montag, 8. März 2004, 18:00–21:00, Bereich C

Epitaxial Ag-films grown on silicon-on-insulator substrates — •Marcin Czubanowski, Christoph Tegenkamp, and Herbert Pfnür — Institut Für Festkörperphysik, Appelstr.2 D-30167 Hannover,Germany

Studies of the conductivity of ultrathin metallic films that are only a few monolayers thick is physically interesting and technically challenging. In order to make the system simple, the influence of the underlying substrate should be reduced to a minimum. Therefore, we performed adsorption experiments of Ag grown under ultra–high vacuum conditions on silicon on insulator (SOI) substrates. The morphology and chemistry of the surface was checked by means of LEED and Auger spectroscopy. To obtain clean and smooth SOI(100) surfaces, the native oxide layer was removed first by adsorption of Si forming volatile SiO. Because the temperatures used for cleaning the surface are lower than 1050 K, the buried oxide layers remain intact and the topmost SOI-film remains undamaged [1]. For (100)–orientated silicon surfaces, Ag grows at low temperatures layer–by–layer in (111)–orientation [2]. An important epitaxy parameter is the growth temperature, which allows to control the defect concentrations within the Ag–films. Best results with respect to large Ag islands were obtained for substrate temperatures of 130 K. The conductivity measurements are done in–situ in a Van der Pauw geometry. First conductivity measurements for different Ag coverages an adsorption temperatures will be presented.
(1) M. Czubanowski et.al., submitted to APL. (2) Horn von Hoegen et.al., Surface Science vol.331-333 (1995) 575.