A method for forming a fine pattern of a semiconductor device includes
forming a first hard mask layer over a semiconductor substrate and a
second hard mask layer over the first hard mask layer, selectively
etching the second hard mask layer and the first hard mask layer by using
a line/space mask as an etching mask to form a second hard mask layer
pattern and a first hard mask layer pattern, forming an insulating film
filling the second hard mask layer pattern and the first hard mask layer
pattern, selectively etching the second hard mask layer and its
underlying first hard mask layer pattern by using the insulating film as
an etching mask to form a fourth hard mask layer pattern overlying a
third hard mask layer pattern, removing the insulating film and the
fourth hard mask layer pattern, and patterning the semiconductor
substrate by using the third hard mask layer pattern as an etching mask,
to form a fine pattern.