The Preparation And Characteristics Representation Of Titanium Dioxide (TiO₂) Thin Film

Titanium dioxide(TiO2) owned a programming prospect in industrial application because of its eminent characteristics in gas-sensing, humidity-sensing, photocatalytic, photovoltaic, self-cleansing, etc. TiO2 thin film gas sensor, with its excellent property consistency, easy integration and some other advantages, gets more and more favorites and attention from the people. To develop TiO2 thin film gas sensor, the priority should be located in understanding and ameliorating its microstructure and properties. This experiment deposited the TiO2 thin film by magnetron sputtering method in different substrate temperature. The As-grown films were treated with different annealing temperature and time. With the application of Atomic Force Microscope (AFM), X-ray Diffractometer (XRD), Scanning Electron Microscope (SEM), their superficial morphology and structure were studied. The results were as follows:(1). The relationship between sputtering conditions and the depositional speed shows: with working pressure 1.2 Pa, sputtering power 180W, the depositional speed of TiO2 thin film is 40nm/h, and increases with the increasing of sputtering power. It can be also founded that the depositional speed is nearly proportional to the working pressure: within the range of 0.3Pa to 1.6Pa, the depositional speed increases linearly with the increase of Ar pressure. With the enhancement of the substrate's temperature of sputtering or annealing, the resulted thin films show a tendency of decreasing in thickness, and increasing in refractivity.(2). The TiO2thin film deposited at room temperature is amorphous. The one deposited at 300 ℃ substrate temperature owns denser crystallites. During the annealing process, with the increasing of annealing temperature, the crystallites become bigger, and crystalline phase begins to transfer. When the annealing temperature gets to 800℃, TiO2 transfers to rutile structure completely.(3). The contact angle with water is 64?for the thin film without annealing. After 650癈 annealing treatment, the contact angle becomes 0°. With proper SnO2 doping, the hydrophilicity of TiO2thin film will be also improved.