Abstract Analyses of the phase composition and electrical characterization of double-layer CeO 2/YSZ and single-layer CeO 2, YSZ dielectrics grown on a Si (100) substrate at 200°C by electron beam evaporation as well as of the quality of interfaces between the oxide layers and silicon substrates were performed. The structure of all investigated oxide layers was found to be of the fcc fluorite type. The electrical conductivity of the investigated oxide layers and the average grain size change due to the post-deposition thermal treatment. The temperature dependence of the activation energy of the electrical conductivity is associated with different impurity phases in the oxide layers. Due to the lowest density of defects assessed from deep-level-transient-spectroscopy (DLTS) measurements, the CeO 2/Si interface seems to be an optimum compared to the other oxide layer configurations. The dielectric constants ε r(YSZ)=18.3 and ε r(CeO 2)=3.4 were estimated from the accumulation capacitances of the C– V curves.