Patent ID: 7927949
Filing Date: 2011-04-19
Classification: H01L

Abstract:
1. A semiconductor memory device manufacturing method comprising: forming a tunnel insulating film on a semiconductor substrate; forming a floating gate electrode on the tunnel insulating film; forming an element isolation trench by etching the floating gate electrode, tunnel insulating film, and semiconductor substrate; forming a first element isolation insulating film on an exposed surface in the element isolation trench; forming a second element isolation insulating film on the first element isolation insulating film; selectively removing the first and second element isolation insulating films to expose a first side-surface portion in an upper portion of the floating gate electrode and a side-surface portion in an upper portion of the first element isolation insulating film; forming a first radical nitride film on surfaces of the floating gate electrode and first and second element isolation insulating films by first radical nitriding; forming an interelectrode insulating film on the first radical nitride film; forming a second radical nitride film on a surface of interelectrode insulating film by second radical nitriding; and forming a control gate electrode on the second radical nitride film, wherein in a second side surface portion in a lower portion of the floating gate electrode, a portion of the first element isolation insulating film exists between the floating gate electrode and the first radical nitride film.