Patent ID: 9130048
Filing Date: 2015-09-08
Classification: H01L

Abstract:
1. A method for manufacturing a semiconductor device, comprising the steps of: forming a gate electrode layer over a substrate having an insulating surface; forming a gate insulating film over the gate electrode layer; forming an oxide semiconductor film having a tapered end face portion over the gate insulating film, wherein the oxide semiconductor film is a c-axis aligned crystalline oxide semiconductor; forming a conductive film over the oxide semiconductor film; etching the conductive film with an etching gas comprising halogen to form a source electrode layer and a drain electrode layer each overlapping with the gate electrode layer and a part of the tapered end face portion; removing an element contained in the etching gas from the exposed rest of the tapered end face portion after etching the conductive film; adding oxygen to the exposed rest of the tapered end face portion after etching the conductive film; and forming a first protective insulating film over the oxide semiconductor film, the source electrode layer, and the drain electrode layer.