| 摘要 |
PROBLEM TO BE SOLVED: To improve charge retention characteristics and to make a gate electrode low in resistance in a nonvolatile memory cell having a split gate structure wherein a MOS type transistor for nonvolatile storage which uses a charge storage film and a MOS type transistor for selecting it are adjacent to each other. SOLUTION: A sidewall of a selection gate electrode 15 is tapered so as to improve charge retention characteristics by suppressing film thinning at a corner part of the charge storage film. Further, the sidewall of the selection gate 15 is recessed so as to stably perform a silicide process for making the gate electrode, formed by self-matching, low in resistance. Alternatively, a step is provided between an upper part 18 of a self-matching gate electrode and an upper part 65 of the selection gate electrode. COPYRIGHT: (C)2011,JPO&INPIT |
