Patent ID: 8084315

Claim:
A method of fabricating a non-volatile semiconductor memory device, the method comprising the steps of: (a) forming a first silicon oxide film on a semiconductor substrate through a plasma film-forming method using a first source gas containing nitrogen and oxygen, and a second source gas containing silicon; (b) after the step (a), introducing nitrogen atoms onto a surface of the first silicon oxide film through plasma nitridation; (c) after the step (b), reacting the nitrogen atoms introduced onto the surface of the first silicon oxide film with the first silicon oxide film through a heat treatment of heating the semiconductor substrate in an atmosphere containing nitric oxide gas to form a silicon oxynitride film on the surface of the first silicon oxide film, and to segregate the nitrogen atoms to an interface between the first silicon oxide film and the semiconductor substrate; (d) after the step (c), forming a first conductive film on the silicon oxynitride film; (e) after the step (d), forming a second silicon oxide film on the first conductive film; (f) after the step (e), forming a second conductive film on the second silicon oxide film; (g) after the step (f), sequentially patterning the second conductive film, the second silicon oxide film, the first conductive film, the silicon oxynitride film, and the first silicon oxide film to form a gate electrode formed of the second conductive film, a second potential barrier film formed of the second silicon oxide film, a charge storage film formed of the first conductive film, and a first potential barrier film formed of the silicon oxynitride film and the first silicon oxide film; and (h) after the step (g), forming a source region and a drain region aligned with the gate electrode in the semiconductor substrate.