Patent ID: 8710498

Claim:
A display device comprising: an oxide semiconductor thin film which is formed above an insulative substrate and includes a first region, and a second region and a third region which are formed on both sides of the first region and have a lower resistance than the first region; a gate insulation film which is formed on the first region of the oxide semiconductor thin film, and exposes the second region and the third region; a gate electrode formed on the gate insulation film; a first interlayer insulation film of silicon nitride, which covers the second region and the third region of the oxide semiconductor thin film, the gate insulation film and the gate electrode, and includes a first contact hole reaching the second region and a second contact hole reaching the third region; a source electrode which is in contact with the second region via the first contact hole; and a drain electrode which is in contact with the third region via the second contact hole, wherein in the first interlayer insulation film which is located immediately above the second region and the third region, an oxygen concentration of a bottom-side portion of the first interlayer insulation film is higher than a central portion which is located at a position corresponding to ½ of a thickness of the first interlayer insulation film.