To provide a nonvolatile semiconductor memory capable of enhancing the breakdown voltage of a high breakdown voltage transistor while reducing the cost, and to provide its fabricating process.
An information memory element having first gate electrodes 3a/4a/5a/6a on a first gate insulating film 2a, a first diffusion layer 7a, and a first diffusion layer insulating film 8a formed thereon, an information operating element having second gate electrodes 3b/4b/5b/6b on a second gate insulating film 2b, a second diffusion layer 7b, and a second diffusion layer insulating film 8b formed thereon, and a signal potential generating element having third gate electrodes 3c/4c/5c/6c on a third gate insulating film 2c thicker than the first gate insulating film 2a and the second gate insulating film 2b, a third diffusion layer 7c, and a third diffusion layer insulating film 8c formed thereon are provided on a first conductivity type semiconductor substrate. The third diffusion layer insulating film 8c is thinner than the third gate insulating film 2c and having a thickness substantially equal to those of the first diffusion layer insulating film 8a and/or the second diffusion layer insulating film 8b.
Takehana Kikuo
Hiroshi Uji