Preparation of homogeneous VO X thin films by ion beam sputtering and annealing process

Abstract

Polycrystalline VO x thin films that were prepared for thermal-sensitive material of far infrared sensor had been deposited on Si substrates by ion beam sputtering deposition. Scanning electron microscopy images indicated that VO x thin films (oxygen pressure of 1.5×10 −3 Pa) were grown into compact and ultra-fine grains (⩽50 nm), the film surfaces seemed smooth and uniform. Four-point probe measurements showed that the homogeneity of the films was better than 98% in a size of 30×30 mm 2. The four-point probe measurement on hot plate presented the sheet resistance and the temperature coefficient of resistance of the VO x thin film that were 50 kΩ/square and −0.021 K −1 at 28°C, respectively. In addition, some samples annealed in Ar atmosphere had their resistance decreased. Thus, vanadium oxide films containing more amount VO 2 were obtained.