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

Abstract

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.

Keywords

• indium‐tin‐zinc‐oxide
• thin film transistors
• anodization
• anodic oxide
• dual channel
• low voltage operation