| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor storage device and a data rewriting method capable of suppressing a decrease in threshold voltage after rewriting with an increase in the number of rewritings. SOLUTION: The electrically rewritable nonvolatile semiconductor storage device conducts an erasing with a hot carrier generated in a drain adjacent end part of a channel forming region by an avalanche breakdown. The channel forming region comprises a first channel forming region of the predetermined region from a drain, and a second channel forming region adjacent to the first channel forming region. Further, an impurity concentration of the second channel forming region is higher than that of the first channel forming region, and a boundary of the two channel forming regions is different from the drain adjacent end part but in an intermediate part between the drain adjacent end part and the source adjacent end part. COPYRIGHT: (C)2009,JPO&INPIT |
