This research is to discuss the sputtering of zinc tin oxide (ZTO) thin film under different oxygen flow conditions in the RF sputtering chamber to conduct a series of verifications and inferences and try to find the best sputtering conditions. Next, we deposited hafnium dioxide (HfO₂) as an insulating layer, and processed zinc tin oxide (ZTO) thin film transistors. By measuring the electrical properties for material analysis, we found that the thin film transistors made of ZTO thin films with an argon-oxygen ratio of 45:5 have a better saturation zone. At the same time, we observe that the transmittance of the film will increase with the increase of the oxygen flow rate, and the transmittance is above 80~85% at the wavelength of visible light. By measuring the Hall effect, we can see that under the condition of an argon-oxygen ratio of 45:5, there is a better carrier concentration of 6.45 ｘ 10¹¹ . This is because the oxygen vacancies in the ZTO film will provide the film carrier. Therefore, when the oxygen concentration is high, the original oxygen vacancies will be filled, thereby alleviating the problem of excessive carrier concentration, and reaching a saturated and cut-off state.