Thin-film transistor and manufacturing method thereof

The invention provides a manufacturing method of a thin-film transistor. The method comprises the steps of sequentially forming a semiconductor layer and a first grid insulating layer on a substrate; forming a photoresist pattern on the first grid insulating layer, wherein the photoresist pattern comprises a first photoresist layer and a second photoresist layer and the thickness of the first photoresist layer is larger than the thickness of the second photoresist layer; adopting the photoresist pattern as a mask, and etching the semiconductor layer and the first grid insulating layer for the first time; removing the second photoresist layer; etching the first grid insulating layer for a second time to remove the thickness of at least one part of the first grid insulating layer that is not covered by the first photoresist layer; removing the first photoresist layer; forming a second grid insulating layer on the first grid insulating layer; and forming a grid on the second grid insulating layer. Based on the above method for manufacturing the thin-film transistor, the sub-threshold swing for driving the thin-film transistor is increased. Meanwhile, the driving performance of an AMOLED is improved.