Manufacturing method of top gate thin-film transistor

A manufacturing method of a top gate thin-film transistor, comprising the following steps:

• Step 1:
• providing a base plate, forming a buffer layer on the base plate, and forming an oxide semiconductor layer on the buffer layer;
• Step 2:
• forming a gate insulation layer and a gate electrode on the oxide semiconductor layer in a manner of being stacked in sequence from bottom to top, such that the gate insulation layer and the gate electrode cover a middle zone of the oxide semiconductor layer with two ends of the oxide semiconductor layer exposed;
• Step 3:
• forming a reducing metal layer on the two exposed ends of the oxide semiconductor layer;
• Step 4:
• subjecting the oxide semiconductor layer that is covered with the reducing metal layer to laser annealing in order to reduce the oxide semiconductor layer that is covered with the reducing metal layer to conductors that form a source contact zone and a drain contact zone respectively located at two ends of the oxide semiconductor layer;
• Step 5:
• subsequently forming an interlayer insulation layer on the gate electrode, the source contact zone, and the drain contact zone and a first via and a second via extending through the interlayer insulation layer, such that the first via and the second via respectively expose the source contact zone and the drain contact zone;
• and
• Step 6:
• forming a source electrode and a drain electrode on the interlayer insulation layer, such that the source electrode and the drain electrode are respectively set in contact with the source contact zone and the drain contact zone through the first via and the second via;
• wherein the reducing metal layer comprises two parts that are respectively formed on the two exposed ends of the oxide semiconductor and are separate from each other such that laser annealing is applied only to the two exposed ends of the oxide semiconductor layer;
• wherein in Step 3, the reducing metal layer is formed of a material comprising manganese or aluminum;
• and
• wherein in Step 3, the reducing metal layer has a thickness less than 100 Å.