Integrated circuit having a memory cell transistor with a gate oxide layer which is thicker than the gate oxide layer of a peripheral circuit transistor

摘要

A gate insulating film in a memory cell portion is thicker than a gate insulating film in a peripheral circuitry. Source/drain of an MOS transistor in the memory cell portion have double-diffusion-layer structures, respectively, and source/drain of an MOS transistor in the peripheral circuitry have triple-diffusion-layer structures, respectively.