Dresden 2006 – scientific programme
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DF: Dielektrische Festkörper
DF 7: Dielectric and Ferroelectric Thin Films and Nanostructures II
DF 7.3: Talk
Wednesday, March 29, 2006, 15:10–15:30, K{\"O}N Farb
Impedance spectroscopy study of thin film capacitors with SrTiO(3) as dielectric — •Kesav Reddy1, Dieter Mergel1, and Werner Osswald2 — 1Thin film working group, Physics Department, University Duisburg-Essen, 45117 Essen — 2Institute for Solid-State Chemistry, Chemistry Department, University Duisburg-Essen, 45117 Essen
Planar thin films capacitors with RuO(2) electrodes and SrTiO(3) as dielectric layer have been prepared by rf-magnetron sputtering. Substrate temperature (up to 700∘C), oxygen content of the sputter gas and thickness of the dielectric layer have been varied.
The capacitors were investigated by x-ray diffraction and impedance spectroscopy in the range 10 Hz to 10 MHz and for temperatures from 20∘C to 200∘C. Contributions from the electrode-dielectric interface, grain boundaries and bulk grains could be distinguished by modelling the spectra with RC-elements. The conductivity and the dielectric permittivity of the bulk SrTiO(3) grains were extracted. The dielectric permittivity ranges from 150 to 350. Its temperature dependence shows Curie-Weiss behaviour with characteristic temperatures between 30 and 50 K.