Enhancement of electrical characteristics of SnGaO thin-film transistors via argon and oxygen plasma treatment

The impact of Ar or O2 plasma treatment on the electrical characteristics of SnGaO thin film transistors (TFTs) fabricated via solution method was examined. The findings of the study revealed that Ar plasma treatment for an optimal duration enhances the electrical properties of SnGaO TFTs, including the improvement of mobility, subthreshold swing (S.S.), and on-off ratio. This result is considered to be due to the increased concentration of oxygen vacancy as donor in the channel layer. Oxygen plasma treatment has an opposite effect on the change in oxygen vacancy concentration, thereby reducing the off-state current and facilitating the adjustment of threshold voltage. However, excessive Ar or O2 plasma treatment duration led to an increase in deep defect states and a significant "hump" phenomenon in the output characteristic curve.