| 摘要 |
A non-volatile semiconductor memory device is provided that includes a semiconductor substrate having a first conductivity type, and diffusion regions having a second conductivity type formed in the surface of the semiconductor substrate at predetermined locations. A gate insulation film is formed on the semiconductor substrate, and a conductive floating gate is formed over the gate insulation film. Additionally, an interpoly insulation film is formed on the upper surface of the floating gate, and a conductive control gate is formed over the interpoly insulation film. Further, the upper surface of the floating gate and/or the upper surface of the interpoly insulation film contain an oxidization suppressing substance. The oxidization suppressing substance suppresses the reaction with the oxidizer during post oxidization, and thus prevents the formation of bird's beaks in the upper and/or lower portions of the interpoly insulation film. Thus, the deteriration of the write/erase characteristics of the memory cells is reduced, and variations in the write/erase characteristics of the memory cells are lessened. The present invention also provides a method of manufacturing such a non-volatile semiconductor memory device.
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