Roles of hydrogen and effects of light annealing in oxide thin film transistors

Abstract

To improve the electrical characteristics and reliability of oxide semiconductor based thin film transistors (oxide-TFTs), several methods have been proposed and researched. In this study, an experiment was performed to identify the effect of hydrogen in oxide TFTs using $Al_2O_3$ layer deposited by atomic layer deposition (ALD) method. Unlike the previously reported negative effects of hydrogen, the beneficial role of hydrogen in oxide TFTs was studied in terms of defect passivation of hydrogen. In addition, a method to improve the performance and reliability of oxide TFT by using light irradiation was demonstrated. Using UV and NIR irradiation on oxide thin film with rapid thermal process (RTP) system, defects of oxide TFTs were effectively eliminated and the superb performances were achieved.