The Effect of Oxygen Partial Pressure during Active Layer Deposition on Bias Stability of a-InGaZnO TFTs
HUANG Xiao-Ming1, WU Chen-Fei2, LU Hai2**, REN Fang-Fang2, ZHU Hong-Bo1, WANG Yong-Jin1**
1Peter Grünberg Research Center, Nanjing University of Posts and Telecommunications, Nanjing 210003 2Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093
Abstract：The effect of oxygen partial pressure (PO2) during the channel layer deposition on bias stability of amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistors (TFTs) is investigated. As PO2 increases from 10% to 30%, it is found that the device shows enhanced bias stress stability with significantly reduced threshold voltage drift under positive gate bias stress. Based on the x-ray photoelectron spectroscopy measurement, the concentration of oxygen vacancies (OV) within the a-IGZO layer is suppressed by increasing PO2. Meanwhile, the low-frequency noise analysis indicates that the average trap density near the channel/dielectric interface continuously drops with increasing PO2. Therefore, the improved interface quality with increasing PO2 during the channel layer deposition can be attributed to the reduction of interface OV-related defects, which agrees with the enhanced bias stress stability of the a-IGZO TFTs.
. [J]. 中国物理快报, 2015, 32(07): 77303-077303.
HUANG Xiao-Ming, WU Chen-Fei, LU Hai, REN Fang-Fang, ZHU Hong-Bo, WANG Yong-Jin. The Effect of Oxygen Partial Pressure during Active Layer Deposition on Bias Stability of a-InGaZnO TFTs. Chin. Phys. Lett., 2015, 32(07): 77303-077303.
2015, Vol. 32 
