Effects of the oxygen pressure on the crystalline orientation and strains of YSZ thin films prepared by E-beam PVD

Yttria-stabilized zirconia, YSZ, thin films were prepared by E-beam physical vapor deposition (PVD) at 200 °C under oxygen pressure of 1 × 10^-3∼1 × 10^-5 Torr. Observations by Field Emission Scanning Electron Microscope (FESEM) proved that different oxygen pressures influenced the thickness of interfacial SiO_x layer formed between the YSZ thin films and Si(100)-substrate. X-ray diffraction (XRD) patterns were used to determine the crystalline structure and calculate the surface grain size of deposited YSZ thin films. XRD patterns also showed that the peaks corresponding to planes (111), (200), (220), and (311) were found and the YSZ thin films revealed the fluorite structure. At lower oxygen pressure (1 × 10^-5∼1 × 10^-4 Torr) YSZ thin films revealed the (111) preferred orientation and at higher oxygen pressure (5 × 10^-4∼1 × 10^-3 Torr) YSZ thin films revealed the (200) preferred orientation. The effects of oxygen pressure on the lattice constants and the internal strains of YSZ thin films were also investigated.