UV irradiation assisted low-temperature process for thin film transistor performance improvement of praseodymium-doped indium zinc oxide

Abstract

Flexible displays have developed rapidly in recent years, low-temperature process to produce high performance amorphous oxide semiconductor devices are significant for the wide application of low-cost flexible display. In this work, praseodymium-doped indium zinc oxide semiconductor deposited by vacuum sputtering was irradiated with UV light before low-temperature thermal annealing. The treated semiconductor retains its characteristics of amorphous and high transparency to visible light. The carrier concentration and oxygen-related defects of the PrIZO films were significant changed under the superposition of UV irradiation and thermal annealing, the effects of UV light and thermal annealing can be well superimposed. The PrIZO-TFT that have been thermally annealed at 200 °C for 1 h after irradiated by UV light with power density of 175 mW cm−2 for 1800 s exhibit an optimal performance (μ sat of 12.34 cm2 V−1·s−1, I on/I off of 3.8 × 108, V th of 0.7 V, SS of 0.15 V/decade) and stability. The device performance broadens the application prospect of AOS TFT in low-cost flexible display.