| 摘要 |
PROBLEM TO BE SOLVED: To provide a technology for making the improvement of the charge holding characteristics of an MOS semiconductor memory wherein device downsizing and variation suppression of the threshold voltage are compatible, and is scarcely influenced by manufacturing variation. SOLUTION: A memory insulating film 4 and a gate insulating film 3 are separately provided on a channel region 13 without a clearance between them, and are provided in the direction orthogonal to the direction where the source region 7 and the drain region 8 are opposed. This portion functions as an electrically rewritable MOS type semiconductor memory cell by having a MONOS type memory insulating film 4 and a second current path 2, and this portion functions as a usual MOS type semiconductor device by having the gate insulating film 3 and the current path 1. Therefore, the threshold voltage after writing is predominant on the gate insulating film 3 side, so that the threshold variation and/or the charge holding characteristics after writing need not be considered. COPYRIGHT: (C)2008,JPO&INPIT
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