Manufacturing method of thin film transistor using oxide semiconductor

Abstract

A manufacturing method of a thin film transistor having at least a gate electrode, a gate insulation film, an oxide semiconductor layer, a first insulation film, a source electrode, a drain electrode, and a second insulation film on a substrate, including: forming the gate electrode on the substrate; forming the gate insulation film on the gate electrode; forming a semiconductor layer including amorphous oxide on the gate insulation film; patterning the gate insulation film; patterning the oxide semiconductor layer; reducing the oxide semiconductor layer in resistance by forming the first insulation film on the oxide semiconductor layer in the atmosphere not including an oxidized gas; patterning the first insulation film and forming a contact hole between the source electrode and the drain electrode and the oxide semiconductor layer; forming a source electrode layer and a drain electrode layer in the oxide semiconductor layer through the contact hole; forming the source electrode and the drain electrode through the contact hole and allowing the first insulation film to be exposed; patterning the exposed first insulation film and allowing a channel region of the oxide semiconductor layer to be exposed; and increasing the channel region in resistance by forming the second insulation film on the surface including the channel region of the oxide semiconductor layer in the atmosphere including an oxidized gas.