Water-Mediated Photochemical Treatments for Low-Temperature Passivation of Metal-Oxide Thin-Film Transistors

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• 作者：Jae Sang Heo ; Jeong-Wan Jo ; Jingu Kang ; Chan-Yong Jeong ; Hu Young Jeong ; Sung Kyu Kim ; Kwanpyo Kim ; Hyuck-In Kwon ; Jaekyun Kim ; Yong-Hoon Kim ; Myung-Gil Kim ; Sung Kyu Park
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：April 27, 2016
• 年：2016
• 卷：8
• 期：16
• 页码：10403-10412
• 全文大小：673K
• 年卷期：0
• ISSN：1944-8252

文摘

The low-temperature electrical passivation of an amorphous oxide semiconductor (AOS) thin-film transistor (TFT) is achieved by a deep ultraviolet (DUV) light irradiation–water treatment–DUV irradiation (DWD) method. The water treatment of the first DUV-annealed amorphous indium–gallium–zinc–oxide (a-IGZO) thin film is likely to induce the preferred adsorption of water molecules at the oxygen vacancies and leads to subsequent hydroxide formation in the bulk a-IGZO films. Although the water treatment initially degraded the electrical performance of the a-IGZO TFTs, the second DUV irradiation on the water-treated devices may enable a more complete metal–oxygen–metal lattice formation while maintaining low oxygen vacancies in the oxide films. Overall, the stable and dense metal–oxygen–metal (M-O-M) network formation could be easily achieved at low temperatures (below 150 °C). The successful passivation of structural imperfections in the a-IGZO TFTs, such as hydroxyl group (OH−) and oxygen vacancies, mainly results in the enhanced electrical performances of the DWD-processed a-IGZO TFTs (on/off current ratio of 8.65 × 10⁹, subthreshold slope of 0.16 V/decade, an average mobility of >6.94 cm² V^–1 s^–1, and a bias stability of ΔV_TH < 2.5 V), which show more than a 30% improvement over the simple DUV-treated a-IGZO TFTs.