A zinc oxide (ZnO) thin film transistor (TFT) and method of forming the same are provided. The ZnO may include a ZnO semiconductor channel, a conductive ZnO gate forming an electric field around the ZnO semiconductor channel, an ZnO gate insulator interposed between the conductive ZnO gate and the ZnO semiconductor channel and an insulating ZnO passivation layer on the ZnO semiconductor channel, the conductive ZnO gate and the ZnO gate insulator to protect the ZnO semiconductor channel, the conductive ZnO gate, and the ZnO gate insulator. A thin film transistor (TFT) may be formed by forming a semiconductor channel, forming a conductive gate having an electric field around the semiconductor channel, forming a gate insulator between the conductive gate and the semiconductor channel, and forming an insulating passivation layer on the semiconductor channel, the conductive gate and the gate insulator.