Asymmetric structure-induced hot-electron injection under hot-carrier stress in a-InGaZnO thin film transistor

This letter investigates the degradation behavior under hot-carrier stress in InGaZnO thin film transistors with I- and U-shaped asymmetric electrodes. After hot-carrier stress, a serious V-t shift, as well as on-current and subthreshold swing degradations are observed in I-d-V-g transfer curve under reverse mode. Moreover, it is found that the V-t instability is caused by hot-electron injection near the drain side, and this phenomenon which is verified by C-V measurement. Furthermore, the location of trapped hot-electron is estimated from the two-stage rise in the gate-to-drain/gate-to-source capacitance curves and then verified by the simulation tool. (C) 2013 AIP Publishing LLC.