Method for fabricating a semiconductor device

A method for fabricating a semiconductor device, the method comprising:

• forming a mold structure on a substrate, such that the mold structure includes inter-electrode insulating films and sacrificial films alternately and repeatedly stacked in a first direction;
• forming a channel hole which penetrates the mold structure in the first direction;
• forming a vertical channel structure inside the channel hole;
• forming a channel insulating film between the vertical channel structure and the mold structure;
• removing the sacrificial films to form trenches which expose the channel insulating film, the trenches extending in a second direction perpendicular to the first direction, each of the trenches being formed between a corresponding pair of adjacent ones of the inter-electrode insulating films;
• and
• forming metallic lines which fill the trenches, respectively, each of the metallic lines being formed as a single layer, using a wet deposition process, each metallic line directly contacting each of inter-electrode insulating films of the corresponding pair of inter-electrode insulating films.