| abstract |
An improvement is made in the reliability of a semiconductor device having a split gate type MONOS memory. An ONO film covering a control gate electrode, and a dummy memory electrode gates are formed, and then a diffusion region on a source-region-side of a memory to produced is formed across the dummy memory electrode gates. Subsequently, the dummy memory electrode gates is removed, and then a memory gate electrode is formed which is smaller in gate length than the dummy memory electrode gates. Thereafter, an extension region on the source-region-side of the memory is formed. |