| 摘要 |
Provided is a semiconductor device having, over the main surface of a semiconductor substrate, a main circuit region and a memory cell array of a flash memory. The memory cell array has a floating gate electrode for accumulating charges of data, while the main circuit region has a gate electrode of MIS.FET constituting the main circuit. In the main circuit region, an insulating film made of a silicon nitride film is formed to cover the gate electrode, whereby miniaturization of elements in the main circuit region is not impaired. The memory cell array has no such insulating film. This means that the upper surface of the floating gate electrode is not contiguous to the insulating film but is covered directly with an interlayer insulating film. According to such a constitution, leakage of electrons from the floating gate electrode of the memory cell array can be suppressed or prevented and the flash memory thus obtained has improved data retention characteristics. |
