Preparation and Characterization of 70TeO<sub>2</sub>-30WO<sub>3</sub> Glass Thin Films by Radio-Frequency Magnetron Sputtering Method

Abstract

70TeO2-30WO3 glass thin films were fabricated using radio-frequency magnetron sputtering method and the effects of processing parameters on the growth rate, the surface morphologies, the crystallinity, and refractive indices of thin films have been investigated using AFM, XRD, SEM, and UV-Vis-IR spectrometer. Amorphous glass thin films with surface roughness of 4~6 nm could be formed only at room temperature and crystalline WO3 phase was observed in all the films prepared at above the room temperature. The deposition rate strongly depended on the processing parameters. It increased with increasing rf power and with decreasing processing pressure. Especially, it changed remarkably as varying the Ar/O2 gas flow ratio from 40sccm/0sccm to 0sccm/40sccm. When the films were formed in pure Ar atmosphere it shows a deposition rate of ~0.2 μm/h, whereas ~1.5 μm/h when the films was formed in pure O2 atmosphere. The refractive indices of TeO2-WO3glass thin films could be measured to be about 1.849~2.165 depending on the wavelength in the range of 500-1100 nm and the bandgap energy of glass thin film was ~3.34 eV.