(華中科技大學(xué) 模具技術(shù)國家重點實驗室，武漢 430074)
摘 要: 將In2O3和SnO2粉末按質(zhì)量比1∶1熱壓燒結(jié)制成靶材， 采用射頻磁控濺射制備了高性能的ITO薄膜。 實驗結(jié)果表明：氬氣壓強(qiáng)對薄膜的電阻率、 可見光透射率TVIL有著重要的影響，其最佳值為0.2 Pa。 ITO膜的方阻、TVIL和顏色與膜厚有著密切的關(guān)系。 提高基體溫度ts可以改善薄膜的性能， 在ts為200 ℃時， ITO薄膜的TVIL達(dá)到90%以上（含玻璃基體）, 方阻為13.1 Ω/□。 根據(jù)薄膜生長的3個階段理論， 建立了薄膜厚度與電阻率的關(guān)系：在ITO薄膜生長過程中， 依次出現(xiàn)熱發(fā)射和隧道效應(yīng)、 逾漏機(jī)制以及Cottey模型導(dǎo)電機(jī)理。由實驗結(jié)果求得了臨界厚度dc約為48~54 nm， AFM表征結(jié)果進(jìn)一步表明ITO薄膜隨著厚度增加表現(xiàn)出不同的導(dǎo)電機(jī)理和尺寸效應(yīng)。
關(guān)鍵字: ITO薄膜； 磁控濺射； 氬氣壓強(qiáng)； 基體溫度； 導(dǎo)電機(jī)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
