Patent ID: 8405140

Claim:
A nonvolatile semiconductor memory device, comprising: a floating gate formed on a semiconductor substrate through a gate insulating film, said floating gate comprising a split type gate comprising a first portion contacting said gate insulating film and a second portion formed on an upper surface of said first portion and extending upwardly from a part of the upper surface of said first portion; a first diffusion layer formed in said semiconductor substrate, and including a plane parallel to a surface of said semiconductor substrate; a second diffusion layer formed in said semiconductor substrate and including said plane; a control gate provided near said floating gate above a channel region in said semiconductor substrate and formed on a first side of said first portion; a conductive film connected with said first diffusion layer and formed on a second side of said first portion and a first side of said second portion through a first insulating film; a second insulating film that abuts the upper surface of said first portion; and a third insulating film, different from said second insulating film, disposed on an upper surface of said second portion.