磁控溅射制备纳米TiO_2薄膜导电性的研究

Conductivity of Magnetron-sputtered Nanometer TiO_2 Thin Films

研究了在纳米厚度范围内,TiO_2薄膜的导电性与薄膜厚度和基底材料的关系.利用射频磁控溅射方法,使用高纯Ti(99.99％)靶,通入Ar和O_2的混合气体,制备了TiO_2薄膜,薄膜膜厚15～225nm.在室温下测量了不同厚度TiO_2薄膜的电阻率,发现TiO_2薄膜的导电性,先后在导体、半导体和绝缘体范围变化.这归因于基底材料与TiO_2的功函数不同,导致了界面电子的转移,功函数差决定了电子转移的深度.

The conductivity of nanometer TiO2 thin films was studied. The dependence of the conductivity of TiO2 thin films on the thickness of the film and the substrate materials were educed. The TiO2 films were deposited by reactive magnetron sputtering of Ti target in an Ar+O-2 mixture in a conventional sputtering reactor. The thickness of the films varied in the range from 15nm to 225 nm. The electrical resistivity of the films was measured at room temperature in the air. The results show that the conductivity of TiO2 thin films varies from metal, semiconductor to nonconductor. This is attributed to the transfer of the electrons at the interface between the TiO2 and substrates, and the difference of work function determines the depth of the transfer of the electrons.