Thin Film Transistor and Display Apparatus Comprising the Same

Disclosed is a thin film transistor, a method for manufacturing the same and a display apparatus comprising the same, wherein the thin film transistor includes a first insulating layer on a substrate, an active layer on the first insulating layer, and a gate electrode spaced apart from the active layer and configured to have at least a portion overlapped with the active layer, wherein the active layer has a single crystal structure of an oxide semiconductor material, and an upper surface of the first insulating layer which contacts the active layer is an oxygen (O) layer made of oxygen (O).