Low-Voltage, High-Performance, Indium-Tin-Zinc-Oxide Thin-Film Transistors Based on Dual-Channel and Anodic-Oxide

Abstract

Oxide semiconductor thin-film transistors (TFTs) with low-voltage operation, excellent device performance, and bias stability are highly desirable for portable and wearable electronics. Here, the development of low-voltage indium-tin-zinc-oxide (ITZO) TFTs with excellent device performance and bias stability based on a dual-channel layer and an anodic-oxide dielectric layer are reported. An ultra-thin anodic AlxOy film as a gate dielectric layer is prepared using an anodization process. The dual-channel layer consists of an oxygen-uncompensated channel layer and an oxygen-compensated capping layer. It is confirmed that the dual-channel structure is effective for enhancing device performance and bias stability in comparison with the single-channel structure. As a result, the dual-channel ITZO TFT gated with anodic AlxOy exhibits an effective saturation mobility of 12.56 cm2 Vs−1, a threshold voltage of 0.28 V, a subthreshold swing of 76 mV dec−1, a low-voltage operation of 1 V, and good operational stability (threshold voltage shift (ΔVTH) ˂ −0.03 V under a negative gate bias stress and ΔVTH ˂ 0.15 under positive gate bias stress of 3600 s). The work shows that the ITZO TFTs, based on a dual-channel layer and an anodic-oxide gate dielectric layer, have great potential for low-power, portable, and wearable electronics.