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MM: Fachverband Metall- und Materialphysik

MM 35: Poster Session II

MM 35.19: Poster

Mittwoch, 25. März 2009, 16:30–18:30, P4

Electrical characteristics of metal-Nb:STO interfaces — •Gesine Saucke, Jörg Hoffmann, and Christian Jooss — Georg-August-Universität Göttingen, Göttingen, Germany

Because of the chemical stability and the small lattice mismatch, strontium titanate (STO) is a widely used substrate material for many perovskite oxides. In addition the conductivity can be tuned by doping with Nb from insulting to a low-resistance behaviour. Therefore Nb:STO is not only of particular importance for deposition of perovskites, but also for the fabrication of novel devices like heterostructures, tunnel- or pn-junctions. In order to examine devices like this, it is important to understand the electrical contact to Nb:STO.

In the vicinity of metallic contacts Schottky barriers are formed, which give rise to a highly non-linear current-voltage relation in two-point configuration. However, the interface resistance not only depends on the work function of the involved materials, but also on the detailed defect structure, e.g. related to the deposition method. In this contribution we summarise our results concerning the fabrication of metallic contacts like Ti, Au, Ag on Nb:STO prepared by sputter deposition techniques with respect to pre-treatment of the substrates, choice of electrode materials and additional post annealing steps.