Patent ID: 8865555
Filing Date: 2014-10-21
Classification: H01L

Abstract:
1. A method for manufacturing a semiconductor device comprising the steps of: forming a first insulating film over a substrate; forming a first oxide semiconductor film over the first insulating film; forming a depression in the first insulating film and forming a second oxide semiconductor film by selectively etching the first insulating film and the first oxide semiconductor film; forming a second insulating film over the first insulating film and the second oxide semiconductor film; forming a third insulating film over the second insulating film; forming a fourth insulating film in contact with side surfaces of the depression and the second oxide semiconductor film, and a fifth insulating film in contact with a side surface of the fourth insulating film by polishing the second insulating film and the third insulating film so that the fourth insulating film and the fifth insulating film are provided in the depression; forming a source electrode and a drain electrode over the second oxide semiconductor film; forming a sixth insulating film over the second oxide semiconductor film, the source electrode, and the drain electrode; and forming a gate electrode over the sixth insulating film.