Property study of aluminium oxide thin films by thermal annealing

Aluminium oxide thin films had been prepared by off-plane filtered cathodic vacuum arc (FCVA) under the oxygen partial pressure of 5 × 10-4 Torr at room temperature. Annealing effects on the properties of the films between 200 °C and 900 °C were investigated. Experiments results showed that the surfaces of aluminium oxide thin films remained smooth up to 600 °C. Crystallization is induced for the film annealed at 900 °C. It was also found that refractive index of the films increased with increasing the annealing temperature. Strong frequency dispersion of refractive index was found and fitted to a single oscillator model. The dispersion parameters, such as single oscillator energy, dispersion energy, average oscillator strength and its related wavelength, were estimated