Ultra-High-Speed Intense Pulsed-Light Irradiation Technique for High-Performance Zinc Oxynitride Thin-Film Transistors

Abstract

In this study, we investigated the effects of intense pulsed light (IPL) on the electrical performance properties of zinc oxynitride (ZnON) thin films and thin-film transistors (TFTs) with different irradiation energies. Using the IPL process on the oxide/oxynitride semiconductors has various advantages, such as an ultrashort process time (similar to 100 ms) and high electrical performance without any additional thermal processes. As the irradiation energy of IPL increased from 30 to 50 J/cm(2), the carrier concentration of ZnON thin films decreased from 5.07 x 10(19) to 9.96 X 10(16) cm(-3) and the electrical performance of TFTs changed significantly, which is optimized at an energy of 40 J/cm(2) (field effect mobility of 48.4 cm(2) V-1 s(-1)). The properties of TFTs, such as mobility, subthreshold swing, and hysteresis, and the stability of the device under negative bias degraded as the irradiation energy increased. This degradation contributed to the change in nitrogen-related bonding states, such as nonstoichiometric ZnxNy and N-N bonding, rather than that of oxygen-related bonding states and the atomic composition of ZnON thin films. Optimization of the IPL process in our results makes it possible to produce high-performance ZnON TFTs very fast without any additional thermal treatment, which indicates that highly productive TFT fabrication can be achieved via this process.