Effect of NH3 plasma treatment on the device performance of ZnO based thin film transistors

We fabricated an enhancement-mode thin film transistor (TFT) using ZnO as an active channel layer deposited by radio frequency (rf) magnetron sputtering. The NH3 plasma passivation was performed in order to improve the electrical properties of the ZnO TFTs. We observed that the NH3 plasma treated ZnO TFTs revealed improved device performances, which include the field effect mobility of 34 cm2/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 105. These results demonstrate that NH3 plasma treatment could effectively enhance the performance of the ZnO based TFT device.

Research highlights
► Enhancement-mode TFT based on ZnO as an active channel layer deposited by rf magnetron sputtering.
► NH3 plasma treatment was performed to improve the TFT performance.
► Significant improvement of device property was achieved by the plasma treatment.
► The detailed results are discussed.