Achievement of high mobility and high stability DG IGZO TFTs with low thermal budget

Abstract

Achieving high mobility, robust stability, and low thermal budget simultaneously in oxide thin-film transistors (TFTs) remains a key challenge for next-generation displays and flexible electronics. We propose an optimized strategy for amorphous In–Ga–Zn–O (a-IGZO) TFTs by combining oxygen plasma pretreatment with a dual-gate architecture, enabling a synergistic enhancement in all three key performance metrics. A 1 min oxygen plasma treatment prior to atomic layer deposition of Al₂O₃ top dielectric promotes favorable trimethylaluminum adsorption and suppresses lattice damage, resulting in a high field-effect mobility of 30.99 cm²/V·s and robust ambient stability. The dual-gate structure further increases device mobility to 44.99 cm²/V·s and improves bias stress stability (ΔV_TH-PBTS/NBTS = +0.08 V/−0.05 V). Notably, the entire fabrication process is carried out at a maximum temperature of only 150 °C, demonstrating a low thermal budget. Furthermore, TCAD simulations are performed to verify that the dual-gate architecture facilitates bulk conduction across the channel, effectively suppressing interface trapping and enhancing bias-temperature-stress stability. This study offers a practical strategy for optimizing TFT performance parameters, with promising applications in high-performance, low-temperature, and flexible electronics.