講演情報
[19p-A302-5]Negative Bias Stability Improvement of In2O3:H TFTs by Yttria Passivation
〇(PC)Prashant Ghediya1, Yusaku Magari1, Yuqiao Zhang2, Yasutaka Matsuo1, Hiromichi Ohta1 (1.RIES-Hokkaido Univ., 2.IQST-Jiangsu Univ.)
キーワード：
In2O3 thin film transistor、Desorption、Negative bias stability
Polycrystalline In2O3:H-based thin-film transistors (TFTs) might be possible alternatives to commercialized amorphous In–Ga–Zn–O TFTs because of their higher field effect mobility (μFE) (~100 cm2 V−1 s−1). However, In2O3:H-based showed large negative bias stress (NBS) threshold voltage (Vth) shifts. Here we show that negative bias stability of high mobility (~90 cm2 V−1 s−1) polycrystalline In2O3:H-TFTs would be significantly improved by yttria passivation. In2O3:H-TFTs without passivation showed extremely large NBS Vth shifts due to the desorption of absorbed gas species that occurred. We clarified the gas species is composed of O2 and H2O by the thermal desorption spectroscopy of In2O3:H films. When a negative bias is applied, desorption of OH− occurs and the OH− releases electrons. Finally, we performed the device passivation using yttria as the passivation layer. The resultant In2O3:H-based TFTs showed excellent NBS stability, indicating that the desorption of OH− was successfully prevented by the yttria passivation.