Patent ID: 8916424
Filing Date: 2014-12-23
Classification: H01L

Abstract:
1. A method for manufacturing a semiconductor device comprising the steps of: forming an oxide semiconductor film over a first oxide insulating film; etching the oxide semiconductor film to form an island-shaped oxide semiconductor film; forming an insulating film over the island-shaped oxide semiconductor film; forming a gate electrode over the insulating film; forming sidewalls in contact with side surfaces of the gate electrode; etching part of the insulating film where the gate electrode and the sidewalls do not overlap to form a gate insulating film; forming a second oxide insulating film over the gate electrode, the sidewalls, and the island-shaped oxide semiconductor film; forming a metal film over the second oxide insulating film; adding oxygen to the metal film to form a metal oxide film, and adding oxygen also to the second oxide insulating film; forming an interlayer insulating film over the metal oxide film; and forming a pair of contact plugs electrically connected to the island-shaped oxide semiconductor film through openings in the interlayer insulating film, the metal oxide film, and the second oxide insulating film.