High-Performance Thin Film Transistor with an Neodymium-Doped Indium Zinc Oxide/Al2O3 Nanolaminate Structure Processed at Room Temperature

Abstract

In this work, a high-performance thin film transistor with an neodymium-doped indium zinc oxide (Nd:IZO) semiconductor via a room temperature approach and adopting the Nd:IZO/Al2O3 nanolaminate structure was investigated. The effects of the ultrathin Al2O3 layer and the thickness of Nd:IZO layer in the nanolaminate structure on the improvement of electrical performance and stability of thin film transistors (TFTs) were systematically studied. Besides the carrier movement confined along the near-channel region, driven by the Al2O3 layer under an electrical field, the high performance of the TFT is also attributed to the high quality of the 8-nm-thick Nd:IZO layer and the corresponding optimal Nd:IZO/Al2O3 interface, which reduce the scattering effect and charge trapping with strong M–O bonds in bulk and the back-channel surface of Nd:IZO, according to the X-ray reflectivity (XRR), X-ray photoelectron spectroscopy (XPS), and micro-wave photo conductivity decay (μ-PCD) results. As a result, the Nd:IZO/Al2O3 TFT exhibits an outstanding performance, with a high μsat of 32.7 cm2·V−1·s−1, an Ion/Ioff of 1.9 × 108, and a low subthreshold swing (SS) value of 0.33 V·dec−1, which shows great potential for the room temperature fabrication of TFTs in high-resolution or high-frame-rate displays by a scalable, simple, and feasible approach.