Characterization of yttria-stabilized zirconium oxide buffer layers for high-temperature superconductor thin films

We have employed transmission electron microscopy and x-ray diffraction to investigate the properties of yttria-stabilized zirconium oxide (YSZ) sputter deposited on silicon. It is shown that the as-deposited YSZ films are polycrystalline (grain size 7-20 nm) with microvoids between grains. Anneals of these films at temperatures of 800, 950, and 1100 °C for 1 h eliminate the microvoids and cause the grain size to increase from 20 to 50 nm at the higher anneal temperatures. Particular texture of the YSZ film is controlled by the details of the deposition conditions. Resistivity measurements of superconducting films deposited on silicon using these buffer layers are also presented.