Patent ID: 8546216

Claim:
A method of fabricating a nonvolatile semiconductor memory device, comprising: forming a first insulating film on a semiconductor substrate; forming a charge storage layer on the first insulating film; forming an element isolation trench in the charge storage layer, the first insulating film and the semiconductor substrate, thereby dividing the charge storage layer into a plurality of parts; forming an element isolation insulating film in the element isolation trench so that at least a part of the charge storage layer is exposed; forming a second insulating layer on the exposed surface of the charge storage layer and the element isolation insulating film by stacking a first silicon nitride film, a first silicon oxide film, an intermediate insulating film having a relative dielectric constant of not less than 7 and a second silicon oxide film sequentially; and forming a control electrode on the second insulating layer, wherein an oxidation treatment is executed after the first silicon nitride film has been formed, or immediately after the first silicon oxide film has been formed and before the intermediate insulating film is formed.