Enhancement of Gate-Bias and Current Stress Stability of P-Type SnO Thin-Film Transistors with SiNx/HfO2 Passivation Layers

In this letter, we report enhanced gate-bias and current stress stability of p-type SnO thin-film transistors passivated with SiNx/HfO2 layers. The improvement is primarily attributed to the effective suppression of bias-induced adsorption of oxygen molecules on the back-channel surface by the presence of passivation layers. Under the gate-bias stress of 10 V and -10 V for 10000 s, the threshold voltage shifts for the passivated TFT are 0.75 V and -0.42 V, respectively, while the corresponding values for the unpassivated one are 1.24 V and -0.77 V. Under the current stress of 2.5 mu A for 10000 s, the threshold voltage shift is -0.29 V for the passivated TFT and -0.63 V for the unpassivated one.