Structure, phase composition and electrical conductivity of thin yttria-stabilized zirconia (YSZ) films deposited by electron beam evaporation on a silicon (1 0 0) substrate at different temperatures i.e. room temperature (r), 700 and 830 degrees C, as well as the quality of the YSZ-Si interface have been investigated. The phase composition was verified by Raman spectroscopy and by infrared (i.r.) transmission measurements. The structure of films changed in agreement with their electrical conductivity depending on the deposition temperature. Both structure and thereby electrical conductivity were influenced by the high concentration of Y2O3 stabilizer used and by the post-deposition thermal treatment of films. The deposition temperature 3 was also important in determining the quality of the YSZ-Si interface and hence the accessible sweep of the surface potential. The capacitance-voltage characteristics of the metal-insulator-semiconductor (MIS) structures incorporating YSZ films measured at r showed hysteresis and positive shifts of the flat-band voltages.