| Tungsten Oxide is a kind of important multifunctional semiconductor material. It has very good properties on electrochromic,gasochromic and gas sensing. Pure WO3 film has lower sensitiveness and selectivity than doped WO3 thin film, after doped Ti in WO3 thin film.And it will hold the crystals of growth , decrease of the film size, increase rate of the pore ,and increase the surface and has more superior performance of gas sensing property as pure WO3 film. In present, the majority of studies are about WO3 film sol-gel method. While fewer studies are about DC-reactive magnectron sputtering technology prepared of Ti-doped WO3 thin films. In this paper DC-reactive magnectron sputtering technology prepared of Ti-doped WO3 thin films is used. Through the study on construction of WO3 film with titanium, to find out the relationship between optical character, the electrical characteristics and anneal temperature analysis with a membrane filter parameter's performance, then find out the best Ti-doped content, which is important to improve WO3 film gas sensing and prepare good performance thin film.With direct control magnetron sputtering process we have prepared Series WO3 film with different O2 pressure(15%,20%,25%,30%,45%) and Ti-doped content (1%,3%,5%). The sample, annealed for an hour with 350℃, 450℃, 550℃temperatures in NO2 atmosphere, will has gotten a better process parameters. In the paper, the research uses aspectrophotometer, XRD, and the hall test for the preparation of the means test and analyses Ti-doped WO3 film. Study is also made on the thickness, optical character, microstructures and the electrical performance data of Ti-doped WO3 film.Analysis shows that after the annealing the WO3 film for hexagonal structure, the diffraction peak has cleared width of phenomenon. It demonstrated that Ti ion had entered WO3 crystal, topaz curbs the growth of WO3; as the test results of hall, the carrier concentration of the S3 is lower and the sample of S3-B-3# is the lowest. We set up WO3 film performance test system, doing a series test for the film according to O2 pressure; anneal temperature, work temperature and Ti-doped content to study the film gas sensing perpoty, and find out the best absolution of process, anneal temperature and work temperature. Test results indicate that there is good sensitivity for NO2 gas when the samples (S3-B-3#) are under in 200℃work temperature. We have summarized the number of metal oxides film sensitive mechanism model according to the influence of size and the experimental results about WO3 film, and adulterated the sensitivity mechanism of Ti-doped WO3 thin films. Analysis has indicated that sufficed quantum Ti-doped into WO3 thin films will improve the film's gas sensing performance.
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