Nonvolatile semiconductor memory device and method for fabricating the same

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

• forming a first conductive film for forming a plurality of word lines in a memory cell array formation region of a semiconductor substrate for a nonvolatile semiconductor memory device and forming a second conductive film in a semiconductor device formation region of the semiconductor substrate;
• forming openings in the first conductive film by a first dry etching process using a first mask such that the word lines in the memory cell array formation region are located apart from one another;
• forming sidewall insulating films for the word lines in the openings formed in the first conductive film;
• removing parts of the sidewall insulating films located adjacent to the ends of the word lines by wet etching using a second mask;
• and
• removing a part of the first conductive film located around a word line formation region by a second dry etching process using a third mask,
• wherein the first and second conductive films are made of the same layer, and
• the step of forming openings in the first conductive film is carried out such that a part of the first conductive film remaining after the formation of the openings is continuous with the second conductive film to which the part of the first conductive film remaining after the formation of the openings is connected to a part of the semiconductor substrate located outside the memory cell array formation region through a gate insulating film forming part of a semiconductor element.