Effect of NH 3 plasma treatment on the device performance of ZnO based thin film transistors

Abstract

We fabricated an enhancement-mode thin film transistor (TFT) using ZnO as an active channel layer deposited by radio frequency (rf) magnetron sputtering. The NH 3 plasma passivation was performed in order to improve the electrical properties of the ZnO TFTs. We observed that the NH 3 plasma treated ZnO TFTs revealed improved device performances, which include the field effect mobility of 34 cm 2/Vs, threshold voltage of 14 V, subthreshold swing of 0.44 V/dec, off-current of 10 −11 A and on to off ratio higher than 10 5. These results demonstrate that NH 3 plasma treatment could effectively enhance the performance of the ZnO based TFT device.