Electrical stress-induced instability of amorphous indium-gallium-zinc oxide thin-film transistors under bipolar ac stress
- School of Electrical Engineering, Kookmin University, 861-1 Jeongneung-dong, Seongbuk-gu, Seoul 136-702 (Korea, Republic of)
- Semiconductor Laboratory, Samsung Advanced Institute of Technology, Nongseo-Dong, Giheung-Gu, Yongin-Si, Gyeonggi-Do 446-712 (Korea, Republic of)
Bipolar ac stress-induced instability of amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors is comparatively investigated with that under a positive dc gate bias stress. While the positive dc gate bias stress-induced threshold voltage shift ({delta}V{sub T}) is caused by the charge trapping into the interface/gate dielectric as reported in previous works, the dominant mechanism of the ac stress-induced {delta}V{sub T} is observed to be due to the increase in the acceptorlike deep states of the density of states (DOS) in the a-IGZO active layer. Furthermore, it is found that the variation of deep states in the DOS makes a parallel shift in the I{sub DS}-V{sub GS} curve with an insignificant change in the subthreshold slope, as well as the deformation of the C{sub G}-V{sub G} curves.
- OSTI ID:
- 21294344
- Journal Information:
- Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 13 Vol. 95; ISSN APPLAB; ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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