Patent ID: 7049180

Claim:
A method of producing a semiconductor device comprising a plurality of memory transistors arranged in an array and a plurality of word lines serving also as gate electrodes of memory transistors in a same row, arranged extending in a row direction, and repeating in a column direction, an insulating film being formed between the word lines so that the word lines are insulated and isolated from each other, a dimension of the distance between word lines being defined by a thickness of said insulating film, said method of producing a semiconductor device comprising the steps of: forming stacked patterns of first charge storage films comprised of a plurality of films and having a charge storage capability and first word lines on a semiconductor in parallel with each other at predetermined distances, forming a second charge storage film comprised of a plurality of films and having a charge storage capability on surfaces of said first word lines and on semiconductor regions exposed between said first word lines; and forming between said first word lines second word lines having at least parts buried between said first word lines where a second charge storage film interposed.