Nonvolatile semiconductor memory device and method for fabricating the same

Abstract

A first conductive film for forming a plurality of word lines is formed in a memory cell array formation region of a semiconductor substrate for a nonvolatile semiconductor memory device, and a second conductive film is formed in a semiconductor device formation region of the semiconductor substrate. Next, openings are formed in the first conductive film by a first dry etching process such that the word lines in the memory cell array formation region are located apart from one another. Thereafter, sidewall insulating films for the word lines are formed in the openings. Next, parts of the sidewall insulating films located adjacent to the ends of the word lines are removed by wet etching. Next, a part of the first conductive film located around a word line formation region is removed by a second dry etching process. The openings are formed in the first conductive film such that a part of the first conductive film remaining after the formation of the openings is continuous with the second conductive film, which is formed on an active region of the semiconductor substrate located outside the memory cell array formation region so as to be electrically connected to the active region.