| 摘要 |
In a nonvolatile semiconductor memory device, buried diffusion layers are stripped parallel to each other in a surface region of a semiconductor substrate of a first conductivity type, and constitute bit lines. A select-gate electrode is formed on the semiconductor substrate, between source and drain regions, through a first gate insulating film to be parallel to the source and drain regions. At least one side of the select-gate electrode is offset from the source and drain regions. A floating-gate electrode is in contact with upper and side surfaces of the select-gate electrode through second and third gate insulating films, respectively, and with the semiconductor substrate through a fourth gate insulating film. The two sides of the floating-gate electrode at least partly overlap the source and drain regions. A control-gate electrode is formed on the floating-gate electrode to surround the floating-gate electrode through a fifth gate insulating film. The control-gate electrode perpendicularly intersects the source and drain regions to constitute a word line. A method of manufacturing a nonvolatile semiconductor memory device is also disclosed.
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