Editors : B. Yan, S. Higashi, C.C. Tsai, Q. Wang, H. Gleskova
a1 School of Electrical Engineering and Computer Science, Seoul National University, Seoul, Republic of Korea
a2 Samsung Electronics, Yongin-Si, Republic of Korea
a3 Department of Materials Science and Engineering, Seoul National University, Seoul, Republic of Korea
We have investigated the reliability of the inverted-staggered etch stopper structure oxide-based TFTs under negative gate bias stress combined with 400 nm wavelength light illumination and the relationship between the carrier concentration at the channel and the extent of Vth shift. It was found that the photo-induced holes cause the severe Vth degradation at the beginning of stress and the hole trapping rate of a single hole is not altered with the increase of the hole concentration. In oxide-based TFTs, the hole concentration at the channel is the determinant factor of the reliability.