Annealing effect on the performance of fully transparent thin-film transistor(TTFT),in which zinc tin oxide(ZnSnO)is used as the channel material and SiO2as the gate insulator,is investigated.The ZnSnO active layer is deposited by radio frequency magnetron sputtering while a SiO2gate insulator is formed by plasma-enhanced chemical vapor deposition.The saturation field-effect mobility and on/off ratio of the TTFT are improved by low temperature annealing in vacuum.Maximum saturation field-effect mobility and on/off ratio of 56.2 cm2/(V·s)and 3×105are obtained,respectively.The transfer characteristics of the ZnSnO TFT are simulated using an analytical model and good agreement between measured and the calculated transfer characteristics is demonstrated.