Study On TiO₂ Thin Films Deposited By Magnetron Sputtering

Photocatalysis is a new, high efficiency, energy saving and modern enviro nmental protection technology, being widely used in various industries. In many of the photocatalysts, TiO2, because of its cheap, chemical stable, safe, nontoxic, is widely used in many areas. And photocatalytic activity of TiO2 thin film is affected by many factors, such as surface morphology, Ti/O atom ratio, membrane thickness and crystallization(the crystal type and crystallinity of TiO2 thin films). Existing research shows that, The changes of process parameters have important influence on the films surface morphology, composition, thickness and crystallization properties, but the regular between them is not systematic and comprehensive. Therefore, this paper has prepared TiO2 thin film on glass slide by DC reactive magnetron sputtering with different parameters, and study the influence of process parameters on surface morphology, composition, thickness and crystal ization properties.This research has prepared TiO2 thin films under different conditions by changing the process parameters(sputtering power, oxygen partial pressure, deposition temperature, the position of the sample, bogie and annealing), and the features of TiO2 thin films, which contain surface morphology, composition, thickness and crystallinity, are characterized by using x ray diffraction instrument(XRD), scanning electronic microscope(SEM), X-MAX spectrometer, and this study has explored the regular between the changes of process parameters and the characteristics(surface morphology, composition, thickness, crystalization) of TiO2 thin films. The results show that:The performances of TiO2 thin films change with the change in process parameters.(1) With the increase of sputtering power, the surface morphology of TiO2 thin films become more dense, the grain size gets larger, the Ti/O atom ratio improves, and the thickness increases; The surface morphology of thin films(whose oxygen partial pressure is 10%), particle size, Ti/O atom ratio are bigger than other films(whose oxygen partial pressure is 5%); The increase of depositio n temperature is advantageous for the films particles to grow up, and promotes the Ti/O atom ratio closer to 0.5; The surface properties of thin films are better, when the turntable is not opened; The surface particles of thin films are refined by annealing, but the Ti/O atom ratio decreases.(2) The sample position and bogie have a certain impact on the crystallization properties o f TiO2 thin films. When the suspension position is parallel to the center position of titanium target, thin films have a better crystallinity than other position, and the diffraction peak intensity is more significant; when the turntable is not opened,the crystalline properties of TiO2 films are better. The oxygen partial pressure and deposition temperature(300℃, 350℃) have a bigger influence on the crystallinity of thin films. The crystallization of thin films whose oxygen partial pressure is 10% is superior to other films(whose oxygen partial pressure is 5%); When the deposition temperature is 350℃,the crystallization properties of thin film is better than that is 300℃. Sputtering power and annealing have the biggest influence on the crystallization of TiO2 thin films. When the sputtering power is lower, the films are amorphous, and with the increase of sputtering power, the crystalline is getting better; and thin films being annealed have better crystal ine, meanwhile, the rutile crystal diffraction peaks appear.