| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electrically rewritable semiconductor nonvolatile memory device that suppresses the degradation of a tunnel insulating film without increasing an occupation area and has high reliability. <P>SOLUTION: A floating gate electrode includes a region having a high impurity concentration and a region having a low impurity concentration. The region having a high impurity concentration is disposed in a part in contact with a control gate insulating film. The region having a low impurity concentration is disposed in a region in contact with a tunnel insulating film. A fine concavity and convexity is formed in a surface part in contact with the control gate insulating film, of the floating gate electrode. <P>COPYRIGHT: (C)2012,JPO&INPIT |
