Drain-Induced-Barrier-Lowing-Like Effect Induced by Oxygen-Vacancy in Scaling-Down via-Contact Type Amorphous InGaZnO Thin-Film Transistors

Abstract

This investigation considers a method to ameliorate drain induced barrier lowing behavior in amorphous-indium-gallium-zinc-oxide thin-film transistors. The $V_{\mathrm{ th}}$ is found to shift negatively when increasing the $I _{D}$ – $V _{G}$ measurement condition $V _{D}$ from 0.1 to 15 V. The current–voltage curves show that this degradation is caused by the effective channel length ( $L _{\mathrm{ eff}}$ ) being shorter than the mask channel length ( $L$ ). Using the transmission line method to extract $L _{\mathrm{ eff}}$ , we discover that the degradation will be completely suppressed by an annealing treatment. As a result, the degradation mechanism of shorter channel length a-IGZO thin film transistors is due to oxygen-vacancies which are located between the channel and the source/drain junction.