Patent ID: 8785266
Filing Date: 2014-07-22
Classification: H01L

Abstract:
1. A method for manufacturing a semiconductor device, comprising steps of: forming a first oxide insulating film over a substrate; forming an oxide semiconductor film over the first oxide insulating film; performing heat treatment to the oxide semiconductor film; selectively etching the oxide semiconductor film to have an end portion of the oxide semiconductor film, wherein the end portion of the oxide semiconductor film comprises a side surface and a top surface of the oxide semiconductor film; forming a second oxide insulating film over the oxide semiconductor film; selectively etching the second oxide insulating film, thereby forming a protective film covering the end portion of the oxide semiconductor film; forming a pair of wirings in direct contact with the protective film and the oxide semiconductor film; forming a gate insulating film in direct contact with the top surface of the oxide semiconductor film after forming the protective film; and forming a gate electrode overlapping with the oxide semiconductor film over the gate insulating film.