Nonvolatile semiconductor device having a memory cells each of which is constituted of a memory transistor and a selection transistor

A fabricating method for a nonvolatile semiconductor memory device, comprising:

• forming a tunnel oxide film on semiconductor substrate;
• forming a first polysilicon layer on said tunnel oxide film;
• forming an interlayer insulating film on said first polysilicon layer;
• forming a second polysilicon layer on said interlayer insulating film;
• forming a first and a second photoresist patterns on said second polysilicon layer;
• patterning said second polysilicon layer, said interlayer insulating film and said first polysilicon layer using said first and second photoresist patterns as a mask to form a first and a second gate patterns;
• and
• implanting an ion to said semiconductor substrate using said first and second gate patterns as a mask to form a first diffusion region positioned one side of said first gate pattern, a second diffusion region positioned the other side of said first gate pattern and one side of said second gate pattern, and a third diffusion region positioned the other side of said second gate pattern.