MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE

摘要

A method for manufacturing a semiconductor device includes the steps of forming a first insulating film over a first gate electrode over a substrate while heated at a temperature higher than or equal to 450° C. and lower than the strain point of the substrate, forming a first oxide semiconductor film over the first insulating film, adding oxygen to the first oxide semiconductor film and then forming a second oxide semiconductor film over the first oxide semiconductor film, and performing heat treatment so that part of oxygen contained in the first oxide semiconductor film is transferred to the second oxide semiconductor film.

主权项

1. A method for manufacturing a semiconductor device comprising the steps of:
forming a first gate electrode over a substrate; forming a first insulating film in contact with the first gate electrode while heating the substrate at a temperature higher than or equal to 450° C. and lower than a strain point of the substrate; forming a first oxide semiconductor film in contact with the first insulating film; adding oxygen to the first oxide semiconductor film; forming a second oxide semiconductor film in contact with the first oxide semiconductor film after adding the oxygen to the first oxide semiconductor film; performing a first heat treatment after forming the second oxide semiconductor film; etching part of the first insulating film, part of the first oxide semiconductor film, and part of the second oxide semiconductor film, whereby forming a first gate insulating film having a projection, an etched first oxide semiconductor film, and an etched second oxide semiconductor film; forming a pair of electrodes in contact with the etched second oxide semiconductor film; forming a third oxide semiconductor film in contact with the etched second oxide semiconductor film and the pair of electrodes; forming a second gate insulating film in contact with the third oxide semiconductor film; and forming a second gate electrode in contact with the second gate insulating film.