Patent ID: 7776689
Filing Date: 2010-08-17
Classification: H01L

Abstract:
1. A method of fabricating a non-volatile semiconductor memory device, comprising: forming a gate insulating film on a semiconductor substrate; forming a first polysilicon film on the gate insulating film; forming a mask material on the first polysilicon film; patterning the mask material; etching the first polysilicon film, the gate insulating film, and the semiconductor substrate with the patterned mask material thereby forming at least one trench; forming a first silicon oxide film on the mask material, the first polysilicon film, the gate insulating film, and the semiconductor substrate in the at least one trench; forming a silicon-rich silicon oxide film on the first silicon oxide film; forming a polysilizane coating film on the silicon-rich silicon oxide film; forming a second silicon oxide film by oxidation of the polysilazane coating film in a steam atmosphere; planarizing the first and second silicon oxide films with the patterned mask material as a stopper; removing the patterned mask material; forming an intergate insulating film on the patterned first polysilicon film; and forming a second polysilicon film on the intergate insulating film.