Non-volatile semiconductor memory device and a method for fabricating the same

A non-volatile semiconductor memory device comprising:

• a semiconductor substrate having a source region and a drain region each formed by a diffusion layer;
• a first gate insulating film formed on said semiconductor substrate, said first gate insulating film having a window;
• a second gate insulating film formed on said semiconductor substrate within said window;
• a floating gate formed on said first gate insulating film, said floating gate covering fully said second gate insulating film;
• and
• a third gate insulating film formed on said floating gate;
• and
• a control gate formed on said third gate insulating film,
• wherein
• said source region is formed outside of the region where said floating gate is formed;
• said second gate insulating film is formed on said drain region;
• and
• a portion of said control gate covers a portion of the surface of said semiconductor substrate with said third gate insulating film interposed therebetween at a region between said floating gate and said source region.

A non-volatile semiconductor memory device comprising:

• a semiconductor substrate having a source region and a drain region each formed by a diffusion layer;
• a first gate insulating film formed on said semiconductor substrate, said first gate insulating film having a window;
• a second gate insulating film formed on said semiconductor substrate within said window;
• a floating gate formed on said first gate insulating film, said floating gate covering a portion of said second gate insulating film;
• a third gate insulating film formed on said floating gate;
• and
• a control gate formed on said third gate insulating film,
• wherein said source region is formed outside of the region where said floating gate is formed, said second gate insulating film is formed on said drain region, and a portion of said control gate covers a portion of the surface of said semiconductor substrate with said third gate insulating film interposed therebetween at a region between said floating gate and said source region.