Origin of light instability in amorphous IGZO thin-film transistors and its suppression.

ABSTRACT: Radiating amorphous In-Ga-Zn-O (a-IGZO) thin-film transistors (TFTs) with deep ultraviolet light (λ = 175 nm) is found to induce rigid negative threshold-voltage shift, as well as a subthreshold hump and an increase in subthreshold-voltage slope. These changes are attributed to the photo creation and ionization of oxygen vacancy states (V_O), which are confined mainly to the top surface of the a-IGZO film (backchannel). Photoionization of these states generates free electrons and the transition from the neutral to the ionized V_O is accompanied by lattice relaxation, which raises the energy of the ionized V_O. This and the possibility of atomic exchange with weakly bonded hydrogen leads to metastability of the ionized V_O, consistent with the rigid t

SUBMITTER: Mativenga M 

PROVIDER: S-EPMC8285384 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature