| 摘要 |
PROBLEM TO BE SOLVED: To improve the data holding characteristics of a nonvolatile memory. SOLUTION: On a principal plane of a semiconductor substrate 1S, a main circuit region N and a memory cell array MR of a flash memory are disposed. In the memory array MR, a floating gate electrode FG for accumulating information electric charge is disposed, while a gate electrode G of MIS-FET, which constitutes a main circuit is disposed in the main circuit region N. In the main circuit region N, an insulating film 2a consisting of a silicon nitride film is so formed as to cover the gate electrode G. As a result of this structure, element miniaturization can be maintained in the main circuit region N. Meanwhile, there is no insulating film 2a formed in the memory cell array MR, that is, the top face of the floating gate electrode FG is directly covered by an interlayer insulating film 2b, without coming into contact with the insulating film 2a. Consequently, leakage of electric charge (e) of the floating gate electrode FG can be suppressed or prevented in the memory cell array MR, and the data holding characteristics of the flash memory can be improved. COPYRIGHT: (C)2008,JPO&INPIT
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