Preparation method of zinc oxide-based thin film transistor

The invention discloses a preparation method of a zinc oxide-based thin film transistor, and the method comprises the following steps: 1, carrying out the pretreatment of a substrate, preparing an aluminum thin film on the substrate as a gate electrode, and obtaining a first substrate; step 2, preparing a Ta2O5 film on the gate electrode as a gate dielectric layer to obtain a second substrate; step 3, etching an active layer region on the gate dielectric layer through a photoetching stripping method, and preparing a WZO thin film in the active layer region as an active layer to obtain a third substrate; wherein the method for preparing the WZO thin film comprises the following steps: adopting a metal W target material and a ZnO target material, and obtaining the WZO thin film through reactive sputtering; the purity of the W target material is 99.99%, and the purity of the ZnO target material is 99.99%; and 4, etching a source electrode region and a drain electrode region on the active layer through a photoetc