Date
Place
- Room A (Room 325)
- 22. Advanced TFT Backplane Technologies I
- August 20, 2015 (Thursday)
- 09:00 ~ 10:30
- [22-4]
- 10:15 ~ 10:30
- Title:Origin of Negative Transfer Shift Under NBIS of a-InGaZnO Thin Film Transistor Using TCAD Simulation
- Mohammad Masum Billah, MD Delwar Hossain Chowdhury, and Jin Jang (Kyung Hee Univ., Korea)
Abstract: We investigate the effect of negative bias illumination stress (NBIS) of a-InGaZnO thin film transistor using technology computer aided design (TCAD). NBIS with negative gate bias of -20V under blue light shows a prolonged negative transfer shift. The origin of negative shift are commonly assumed as the formation of ionized oxygen vacancy and/or hole trapping at the interface of gate insulator with a-IGZO. Using TCAD simulation, we clarified that the NBIS is due to the increment of Gaussian donor bump density of states (DOS) at 2.9eV as well as acceptor like DOS at 2.5eV to 2.3eV from valance band edge. It also increases the interface charge density at a-IGZO/SiO2 interface, which makes the negative threshold voltage shift with stress time.
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