Patent ID: 9461138
Filing Date: 2016-10-04
CPC Classification: H01L

Claim Text:
1. A non-volatile semiconductor memory comprising: a silicon substrate; a first silicon oxide film; a second silicon oxide film; a third silicon oxide film; a first silicon nitride film; a second silicon nitride film; and a fourth silicon oxide film, wherein the first silicon oxide film and the third silicon oxide film are layered on the silicon substrate, the first silicon nitride film is layered on the first silicon oxide film, the second silicon oxide film is layered on the first silicon nitride film, the third silicon oxide film has a thickness that is smaller than that of the first silicon oxide film, the second silicon nitride film has a first part that is in contact with the first silicon nitride film, the first silicon oxide film and the second silicon oxide film, and a second part that is in contact with and layered on the third silicon oxide film, and the fourth silicon oxide film has a layer structure with the fourth silicon oxide film layered on the second silicon nitride film, which together define a side wall, such that the second silicon nitride film is layered between the fourth silicon oxide film and the third silicon oxide film along a lower surface of the fourth silicon oxide film.