(华中科技大学 模具技术国家重点实验室，武汉 430074)
摘 要: 将In2O3和SnO2粉末按质量比1∶1热压烧结制成靶材， 采用射频磁控溅射制备了高性能的ITO薄膜。 实验结果表明：氩气压强对薄膜的电阻率、 可见光透射率TVIL有着重要的影响，其最佳值为0.2 Pa。 ITO膜的方阻、TVIL和颜色与膜厚有着密切的关系。 提高基体温度ts可以改善薄膜的性能， 在ts为200 ℃时， ITO薄膜的TVIL达到90%以上（含玻璃基体）, 方阻为13.1 Ω/□。 根据薄膜生长的3个阶段理论， 建立了薄膜厚度与电阻率的关系：在ITO薄膜生长过程中， 依次出现热发射和隧道效应、 逾漏机制以及Cottey模型导电机理。由实验结果求得了临界厚度dc约为48~54 nm， AFM表征结果进一步表明ITO薄膜随着厚度增加表现出不同的导电机理和尺寸效应。
关键字: ITO薄膜； 磁控溅射； 氩气压强； 基体温度； 导电机理
（State Key Laboratory of Die and Mould Technology,
Huazhong University of Science and Technology， Wuhan 430074, China）
Abstract: The high quality ITO thin films were prepared at different temperatures by r.f. magnetron sputtering. The results show that Ar partial pressure (p(Ar)) has an important influence on the conductance and transmission in visible range (TVIL). The optimal p(Ar) is 0.2 Pa ascertained by experiments. The sheet resistance, TVIL and color of ITO films depend on the film thickness. The film properties can be improved by elevating substrate temperature (ts). For instance the films with TVIL larger than 90% and sheet resistance 13.1 Ω/□ are obtained when ts is 200 ℃. Based on the growth theory of ITO thin films during the three steps, the relations between the conductivity and the film thickness are established according to thermionic emission and tunneling, percolative form of film conductivity and Cottey model of conductivity mechanism. The critical thickness dc, which is about 48-54 nm, is confirmed by the experiment data. The validity of conductivity mechanism and dimensional effect are confirmed by analysis of AFM for ITO surface.
Key words: ITO thin film; magnetron sputtering; argon partial pressure; substrate temperature; conductivity mechanism
