Patent ID: 9735166
Date: 2017-08-15
CPC Classifications: H01L

Claim:
1. A method of manufacturing a semiconductor device comprising: forming an insulating layer for a gate insulating film and a conductive layer for a floating gate on a principal surface of a semiconductor substrate; forming on the conductive layer for the floating gate, a spacer insulating film, a second insulating film in contact with a side surface of the spacer insulating film, which is composed of a different material from the spacer insulating film and the insulating layer for the gate insulating film, and a first insulating film in contact with a side surface of the second insulating film opposite to the spacer insulating film, which is composed of the same material as the insulating layer for the gate insulating film; forming a floating gate having a tip portion from the conductive layer for the floating gate and exposing a part of the insulating layer for the gate insulating film from the floating gate by removing a part of the conductive layer for the floating gate by using the spacer insulating film, the first insulating film, and the second insulating film as a mask; exposing a part of the tip portion of the floating gate by removing the first insulating film; further exposing the tip portion of the floating gate by selectively removing the second insulating film among the second insulating film, the insulating layer for the gate insulating film, and the spacer insulating film; and forming a control gate on the tip portion exposed from the spacer insulating film, with a tunnel insulating film being interposed.