Stable and High-Performance Flexible ZnO Thin-Film Transistors by Atomic Layer Deposition

详细信息    查看全文

• 作者：Yuan-Yu Lin ; Che-Chen Hsu ; Ming-Hung Tseng ; Jing-Jong Shyue ; Feng-Yu Tsai
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：October 14, 2015
• 年：2015
• 卷：7
• 期：40
• 页码：22610-22617
• 全文大小：353K
• ISSN：1944-8252

文摘

Passivation is a challenging issue for the oxide thin-film transistor (TFT) technologies because it requires prolonged high-temperature annealing treatments to remedy defects produced in the process, which greatly limits its manufacturability as well as its compatibility with temperature-sensitive materials such as flexible plastic substrates. This study investigates the defect-formation mechanisms incurred by atomic layer deposition (ALD) passivation processes on ZnO TFTs, based on which we demonstrate for the first time degradation-free passivation of ZnO TFTs by a TiO₂/Al₂O₃ nanolaminated (TAO) film deposited by a low-temperature (110 掳C) ALD process. By combining the TAO passivation film with ALD dielectric and channel layers into an integrated low-temperature ALD process, we successfully fabricate flexible ZnO TFTs on plastics. Thanks to the exceptional gas-barrier property of the TAO film (water vapor transmission rate (WVTR) < 10^鈥? g m^鈥? day^鈥?) as well as the defect-free nature of the ALD dielectric and ZnO channel layers, the TFTs exhibit excellent device performance with high stability and flexibility: field-effect mobility >20 cm² V^鈥? s^鈥?, subthreshold swing < 0.4 V decade^鈥? after extended bias-stressing (>10鈥?00 s), air-storage (>1200 h), and bending (1.3 cm radius for 1000 times).