The effects of N₂O plasma treatment on the device performance of solution-processed a-InMgZnO thin-film transistors

In this paper, the effects of N2O plasma treatment (PT) at various temperatures on the performances of InMgZnO (IMZO) thin-film transistors (TFTs) were investigated. As a result, the TFTs with N₂O plasma-treated (10 W) IMZO channel layers at 100° for 10 min showed five times higher linear field-effectmobility compared to the untreated IMZO. The N₂O PT did not cause any significant changes to the crystal structure, surface roughness of the IMZO thin films. However, an X-ray photoelectron spectroscopy study confirmed that the oxygen-vacancy defect density of the channel layer decreases via the N₂O PT with temperature increased, and the reduction of oxygen vacancies leads to a decrease of off-current (IOFF). It was found out that the refractivity of the channel layer increases with PT temperature increased, and the improvement of the film density makes the on-current (ION) higher, resulting in high mobility and high ION/IOFF ratio. Our study suggests that moderate N₂O PT temperature can be adopted to improve the device performances.