Anomalous bias-stress-induced unstable phenomena of InZnO thin-film transistors using Ta2O5 gate dielectric

作者：Xu Wangying^*; Dai Mingzhi; Liang Lingyan; Liu Zhimin; Sun Xilian; Wan Qing; Cao Hongtao

来源：Journal of Physics D: Applied Physics , 2012, 45(20): 205103.

DOI：10.1088/0022-3727/45/20/205103

InZnO thin-film transistors using high-kappa Ta2O5 gate dielectric are presented and analysed. The large capacitance coupling effect of amorphous Ta2O5 results in fabricated devices with good electrical properties. However, an anomalous negative threshold voltage (V-th) shift under positive bias stress is observed. It is suggested that electron detrapping from the high-kappa Ta2O5 dielectric to the gate electrode is responsible for this V-th shift, which is supported both by the logarithmical dependence of the V-th change on the duration of the bias stress and device simulation extracted trapped charges involved.

• 出版日期2012-5-23
• 单位中国科学院; 中国科学院宁波材料技术与工程研究所