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Thin film capacitors with BaTiO3 as dielectric and RuO2 as electrode material have been prepared by rf-magnetron sputtering at temperatures up to 750 °C and under various oxygen partial pressures. They have been analyzed by complex impedance spectroscopy in the temperature range 20–200 °C. At about 10 kHz, the grain effect is dominant and the electrical and dielectric properties of the bulk grains can be extracted. The activation energies of the conductivity are in the range 30–100 meV, characteristic for hopping of electrons. The dielectric constant at room temperature ranges from 60 to 1500, depending on the preparation conditions. There is a maximum in the temperature dependence of εr that shifts to lower temperatures when the capacitors have been prepared with more oxygen. Above that temperature, Curie–Weiss behavior is observed with characteristic temperatures in the range 250–400 K. Biggest dielectric permittivity and lowest dielectric loss are obtained for films prepared at 750 °C at medium oxygen partial pressures. With increasing oxygen content the low-frequency semicircle and the effective dielectric permittivity, attributed to grain boundaries or an electrode interface layer, increases for the films prepared at all deposition temperatures. The films prepared with high oxygen partial pressure show increased crystallinity and dense columnar structure.

Conductive ruthenium oxide (RuO2) thin films have been deposited at different substrate temperatures on various substrates by radio-frequency (rf) magnetron sputtering and were later annealed at different temperatures. The thickness of the films ranges from 50 to 700 nm. Films deposited at higher temperatures show larger grain size (about 140 nm) with (200) preferred orientation. Films deposited at lower substrate temperature have smaller grains (about 55 nm) with (110) preferred orientation. The electrical resistivity decreases slightly with increasing film thickness but is more influenced by the deposition and annealing temperature. Maximum resistivity is 861 μΩ cm, observed for films deposited at room temperature on glass substrates. Minimum resistivity is 40 μΩ cm observed for a thin film (50 nm) deposited at 540°C on a quartz substrate. Micro-Raman investigations indicate that strain-free well-crystallized thin films are deposited on oxidized Si substrates.

Thin film capacitors of SrTiO3 with RuO2 top and bottom electrodes on Si substrates were prepared by radio-frequency magnetron sputtering at substrate temperatures 500 and 700 °C and at various oxygen partial pressures. The thickness of the dielectric layer was varied between 200 and 900 nm. The impedance spectra of these samples could be interpreted with an equivalent circuit comprising a resistance and two RC-parallel elements in series. The dielectric permittivity var epsilonr of the bulk grains, as extracted from the high-frequency semicircle in the Cole–Cole plot, was in the range 300–600. High oxygen contents lead to high values of var epsilonr but also increase the grain boundary resistance.