| 摘要 |
To prevent the occurrence of conductive residues that may short-circuit between word lines. A memory cell comprises a channel forming area (CH), charge storage films (CSF) each consisting of a plurality of laminated dielectric films, two storage units consisting of charge storage film (CSF) regions superposed on the opposite ends of the channel forming areas (CH), single-layer dielectric films (DF2) in contact with the top of the channel forming area (CH) between the storage units, auxiliary layers (e.g., bit line (BL1, BL2)) respectively formed on two impurity areas (S/D), two first control electrodes (CG1, CG2) formed on the auxiliary layers via dielectric films and positioned on the storage units, and second control electrode (WL) embedded in a space therebetween insulated form the first control electrodes (CG1, CG2) and in contact with the top of the single-layer dielectric film (DF2). Since the main areas of the facing surfaces of the first control electrodes (CG1, CG2) form forward tapers, no conductive residues remain when the second control electrode (WL) is worked.
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