A Study on the properties of tellurium-oxide thin films based on the variable sputtering gas ratio

Abstract

The properties of tellurium-oxide (TeO x ) thin films were investigated for applications in optical devices. The TeO x thin films were deposited by using the radio-frequency (RF) reactive sputtering method with TeO2 composite and Te metallic targets under various sputtering gas ratios. The effect of the Ar:O2 gas ratio on the composition and on the structural and optical properties of the TeO x thin films was evaluated for the two types of targets. The variation of the stoichiometry of the TeO x thin films was observed by using X-ray photoelectron spectroscopy (XPS). The formation of the Te-O bond was confirmed by using Fourier-transform infrared spectroscopy (FTIR). The O:Te atomic ratio of the TeO x thin films was divided into two ranges (1 < x < 2 and 2 < x < 3) for increasing O2 content in the sputtering gas mixture. Different optical properties were observed in the two groups of TeO x thin films. These study results demonstrated that TeO x is a useful material for realizing optical devices based on various O:Te atomic ratios.