A thin film transistor and a manufacturing method of an array substrate and a display device

Embodiments of the present invention provide a thin film transistor and a manufacturing method of an array substrate and a display device, a thin film transistor structure relates to the field, to solve the conventional thin-film transistor due to the presence of the level difference between the source and the drain electrode in the insulating layer and not the same interface, so that eventually when forming the active layer, the thickness of the source and drain electrodes and the insulating layer is difficult to control the problem of disconnection of the source and drain of the active layer at a channel appears to improve the performance of thin film transistor and stability, reduce production costs. The thin film transistor includes: a gate insulating layer and a gate, wherein the gate at a position corresponding to the gate electrode is provided with a groove on the insulating layer. The present invention is applied to the display art.