Reduced activation energy of nano size phase formation in yttria stabilized zirconia film obtained by RF magnetron sputtering: Preliminary results

Yttria stabilized zirconia (YSZ) is a well-known ceramic material used for many various applications including a buffer layer for growth of functional oxide thin films on Si in semiconducting silicon chip technology. In the present work, YSZ thin film deposition on Si (100) substrate using magnetron sputtering system at room temperature is considered. The films were characterized by several methods: X-ray Photoelectron Spectroscopy (XPS), High Resolution Scanning Electron Microscopy (HRSEM) and X-ray diffraction (XRD). They were used in order to get information regarding the composition and the uniformity of the samples, determine their crystal structure and measure the grain size and the thin films thicknesses, respectively. In addition, the kinetics of the YSZ phase growth was investigated. Several samples were heat treated for one hour in air 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 entire depth of the film. This composition complies with the composition of 8YSZ known in the literature. This was expected since the sputtering target was 8YSZ. A decrease in film thickness and of the crystallization process was observed by XRD and HRSEM. The growth of the YSZ phase and its formation kinetics showed very low activation energy of ∼ 10.6 - 13.5 kJ/mol.