Regensburg 2016 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 39: 1D Metal Wires on Semiconductors II
O 39.7: Talk
Tuesday, March 8, 2016, 15:30–15:45, S052
Local transport measurements on terbium-silicide nanowires — •Frederik Edler1, Ilio Miccoli1, Herbert Pfnür1, Stephan Appelfeller2, Mario Dähne2, Simone Sanna3, Wolf G. Schmidt3, and Christoph Tegenkamp1 — 1Institut für Festkörperphysik, Leibniz Universität Hannover, 30167 Hannover — 2Institut für Festkörperphysik, TU Berlin, 10623 Berlin — 3Lehrstuhl für Theoretische Physik, Universität Paderborn, 33098 Paderborn
Metal silicide wires play an important role in electronics as ohmic contacts and gate electrodes due to their very low resistivity. Rare-earth (RE) metals (eg. Tb, Dy, Er, Y) can be used to grow long, extremely thin nanowires because of uniaxial lattice matching with Si which could be used for additional downscaling of Si based technology.
The transport properties of Tb silicide wires have been studied via 4-tip STM/SEM system. The SEM allows a fast characterization of sample quality and precise positioning of feedback controlled STM tips, enabling gentle contacts and transport measurements on a nm-scale. Moreover, the STM was used to correlate the surface morphology of nanowires with transport findings.
Our measurements reveal three types of metallic wires mainly depending on the growth parameters. Further analysis shows that the resistivity is strongly depending on the height of wires, which is increased for small heights. The data can be perfectly described by a theoretical model taking into account the surface roughness and lateral surface correlation. STS reveals that the wires are electronically decoupled from the Si substrate in agreement with recent DFT calculations.