Method for manufacturing flash memory device

A method for manufacturing a flash memory device, comprising:

• (a) sequentially forming a first gate insulating film, a first gate conductive film, and a second insulating film on a semiconductor substrate;
• (b) defining a region for a first gate by partially etching the second insulating film to expose an upper portion of the first gate conductive film;
• (c) forming second conductive film spacers along sidewalls of the etched second insulating film;
• (d) forming an oxide film on the exposed surface of the second conductive film spacers and the first gate conductive film;
• (e) forming silicon insulating film spacers on sidewalls of the etched second insulating film;
• (f) forming a source junction contact hole by etching the first gate conductive film and the first gate insulating film, using the second insulating film and the silicon insulating film spacers as a mask;
• (g) forming a source junction contact fill by filling the source junction contact hole with a conductive film;
• (h) forming the first gate by sequentially removing the second insulating film and the first gate conductive film beneath the second insulating film;
• (i) forming a second gate insulating film on an exposed sidewall of the first gate;
• (j) exposing upper portions of the source junction contact fill and the second gate conductive film by sequentially forming a second gate conductive film and a silicon nitride film on the semiconductor substrate and removing the silicon nitride film so that it is level with an upper portion of the insulating spacers;
• (k) forming a mask silicon oxide film over the exposed source junction contact fill and the second gate conductive film;
• and
• (l) forming a second gate by sequentially removing the exposed silicon nitride film and the second gate conductive film under the silicon nitride film.