Patent ID: 8207034
Filing Date: 2012-06-26
Classification: H01L

Abstract:
1. A manufacturing method of a semiconductor memory device comprising: forming a first nitride film having a first opening portion on a polysilicon film after forming the polysilicon film on a gate insulating film formed on a substrate; forming a second nitride film on a surface of the first nitride film after forming a first oxide film covering a surface of the polysilicon film exposed in the first opening portion, a side surface of the first nitride film, and an upper surface of the first nitride film; forming a first spacer insulating film having a second opening portion and formed to be a sidewall shape after forming a second oxide film filling the first opening portion and performing an etch back to the second oxide film; removing the polysilicon film and the gate insulating film selectively in the second opening portion after removing the second nitride film and the first oxide film selectively by using the first spacer insulating film as a mask, and filling the second opening portion by polysilicon; performing a selective polysilicon film removal, wherein said performing the selective polysilicon film removal includes: removing the first nitride film to expose a surface of the polysilicon covered by the first oxide film and the first nitride film in a side region of the first spacer insulating film; and removing the polysilicon film selectively by using the first oxide film as a mask; removing the first oxide film on a side of the first spacer insulating film and the gate insulating film being exposed; and forming a control gate after forming a tunnel insulation film.