Analysis of Indium–Zinc–Oxide Thin-Film Transistors Under Electrostatic Discharge Stress

The electrostatic discharge robustness of indium–zinc–oxide thin-film transistor (IZO TFT) was investigated in this brief by employing a transmission line pulsed (TLP) test with different durations. A transition of operation region was observed in the TLP I–V characteristics which may be induced by space charge limited current effects. The experimental results show the breakdown in the long channel IZO TFTs only depends on the stress voltage level, which is related to the gate insulator. Furthermore, the evolution and mechanisms of prebreakdown degradation and latent failure were also presented. Due to hole trapping in the gate insulator and formation of localized states, threshold voltage decreases while electron field-effect mobility and subthreshold swing increase after TLP stress. Moreover, low-frequency noises (LFNs) before and after TLP stress were measured. Spatial distributions of trapped charges in the gate insulator were extracted based on LFN results.