Enhancement of In-Sn-Ga-O TFT performance by the synergistic combination of UV + O<sub class="a-plus-plus">3sub> radiation and low temperature annealing

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• 作者：Hyun-Jun Jeong ; Hyun-Mo Lee ; Keun-Tae Oh ; Jozeph Park…
• 关键词：Oxide semiconductor ; Thin film transistor ; Ozone ; UV
• 刊名：Journal of Electroceramics
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：37
• 期：1-4
• 页码：158-162
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Optical and Electronic Materials; Ceramics, Glass, Composites, Natural Materials; Characterization and Evaluation of Materials; Electrochemistry; Crystallography and Scattering Methods;
• 出版者：Springer US
• ISSN：1573-8663
• 卷排序：37

文摘

High performance thin film transistors (TFTs) based on amorphous In-Sn-Ga-O (ITGO) semiconductor were fabricated. In order to activate the electrical properties of the oxide semiconductor, different processes were used, involving thermal annealing, UV + O<sub>3sub> (UVO) radiation, and UVO-assisted thermal annealing. While either UV radiation or thermal annealing at 150 °C results in rather poor transfer characteristics, the combination of both allows the fabrication of high performance devices with field effect mobility values exceeding 20 cm2/Vs. X-ray photoelectron spectroscopy (XPS) analyses of ITGO films suggest that the density of defects related to oxygen-deficient sites are reduced upon UVO-assisted annealing. Also, hydroxide bonds are found to increase in the semiconductor material, which is highly likely to increase the free carrier concentration. The reduction of oxygen-related defects results in a decrease in charge trap density near the semiconductor/gate dielectric interface, and the UV-assisted annealed ITGO devices exhibit relatively small shifts in the threshold voltage (V<sub>thsub>) under positive bias stress.