Hydrogenated In–Ga–Zn–O thin-film transistors with anodized and fluorinated Al2O3 gate insulator for flexible devices

Abstract

For the purpose of developing In–Ga–Zn–O (IGZO) thin-film transistors (TFTs) on a flexible substrate, low-temperature (150 °C) processed hydrogenated IGZO (IGZO:H) TFTs with anodize alumina gate insulator (Al2O3 GI) have been developed. We found that fluorination of the Al2O3 GI surface significantly improves field effect mobility (μ FE) and positive gate bias and temperature stress (PBTS) reliability of the TFTs. μ FE of 28.8 cm2 V−1 s−1 and good PBTS reliability were obtained from the IGZO:H TFTs with a 68 nm thick fluorinated Al2O3 GI. X-ray photoelectron spectroscopy analysis revealed that fluorine in the AlOF x formed at the Al2O3 surface played an important role in improving performance and PBTS reliability of low-temperature-processed oxide TFTs for future flexible device applications.