A study of titanium dioxide conductive thin films by sputter method in Ar+H2 atmosphere

• Main Authors: Yuan-yu Lin, 林沅昱
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/53487449912769925355

碩士 === 國立聯合大學 === 材料科學工程學系碩士班 === 97 === In this study, TiO2-x thin films was prepared by radio frequency (RF) magnetron sputtering method, using TiO2 as target. The films was deposited at varius H2/Ar flow ratio, working pressure, sputtering power, substrate temperature and substrate bias, under constant pressure of 1x10-3 torr and constant mixture gas H2+Ar flow rate of 40 sccm. The structures of the films was characterized by glancing incident angle X-ray diffractometer (GID), field-emission scanning electron microscope (FE-SEM), X-ray photoemission spectrometry (XPS). UV-Visible spectrometry and four-point probe measurement was done to analyze the optical and electric properties. Conductivity of TiO2-x thin films sputtering in Ar+H2 atmosphere was enhanced due to generation of O-vacancies. The films, deposited at 20H2/20Ar flow ratio, exhibit the lowest resistivity of 2.64×10-3Ω-cm. The results also indicated that average transmittance in visible range decreased with increasing of hydrogen due to reduction effect. The mobility of films was increased due to better crystallization when working pressure was at 1×10-3 torr. The radio-frequency power affected the degree of ionization of hydrogen in the plasma, the sputtering yield and the crystallization, 200W power was found to be the optimum power to obtain low resistivity TiO2-x thin films. The crystalline of films could also be improved by increasing substrate temperature to 400℃, and exhibited highest carrier concentration and mobility. When substrate bias was -200V, that could improve unbalanced resistivity of thin films.