Heat treatment of yttria stabilized zirconia films on silicon substrate prepared by magnetron sputter deposition

Yttria stabilized zirconia (YSZ) is used as a solid electrolyte for applications in gas sensors and fuel cells. In the present work, YSZ thin film deposited on Si (100) substrate using magnetron sputtering is considered. The films were investigated and characterized by several methods: X-ray Photoelectron Spectroscopy (XPS), High Resolution Scanning Electron Microscopy (HRSEM) and X-ray diffraction (XRD). These techniques were used to get information on the composition and the uniformity of the samples, to determine their crystal structure and to evaluate the grain size and the thin films thickness, respectively. In the frame work of this study, the kinetics of the YSZ phase growth was determined. Several samples were heat treated for one hour at various temperatures in the 500-650°C temperature range, which made it possible to estimate the apparent activation energy of the process. The thin film characterization by XPS showed uniformity in composition through the depth of the film. This composition agrees with the expected composition of 8-YSZ (yttria stabilized zirconia) listed in data bases. A decrease in film thickness was observed following the YSZ crystallization as revealed by XRD and HRSEM. The growth of the YSZ phase and the kinetics its formation showed an activation energy of 0.12 eV.