Preparation And Characterization Of VO₂ Thin Films By R.F Magnetron Sputtering

VO₂ is a kind of metallic oxide which undergoes a metal-semiconductor phase transition near 68℃.The phase transforming temperature is close to room temperature and the optoelectronic properties changes a lots during the process. So, it has potential applications in many fields.In this paper, VO₂ thin films is prepared by radio frequency magnetron sputtering and annealed at different temperature in argon atmosphere. It also has been researched that the effects of magnetron sputtering parameters and the annealed treatment to the microstructure and optoelectronic properties. The high-quality VO₂ thin films which the stoichiometric ratio adjacent to the theoretical values is prepared. Research has been done as follows in detail:(1) Preparing high-valence stated V₂O₅ thin films by sputtering on the heated substrates.(2) Deoxidizing V₂O₅ thin films into low-valence stated VO₂ thin films by heat treatment.(3) Study on the effect of films' annealing temperature and time to the films component and properties by comparing and analyzing several samples. It is found out that the critical processing condition is to control the exact annealing temperature and time in experiments.(4) The phase structure, the component and the surface topography of vanadium oxides are analyzed by Raman, XPS, AFM, and SEM. It reveals from Raman and XPS results that the main component in the preparation of V₂O₅ thin films under the condition of 450℃ and 2 hours' annealing is VO₂ phase.(5) The result of measuring electricity properties of VO₂ films reveals that the resistance of the films suddenly changes in 68.3℃ from semiconductor state into metal state. The resistance changes for 2 numeral degrees and the width of hear stagnant loop is 14.5℃. After several heat recycling experiments, VO₂, whose phase-transition characteristics hardly change has steady phase-transition properties.