Method of forming line/space patterns

Abstract

A method of forming a line/space pattern includes forming a plurality of first pattern structures on a layer of hard mask material disposed on a substrate, forming a plurality of second pattern structures along sidewalls of the first pattern structures, removing the first pattern structures such that the second pattern structures stand alone on the layer of hard mask material, forming a first mask that exposes a location where a space of the line/space pattern to be formed is to have a width greater than the distance between adjacent ones of the second pattern structures, removing those of the second pattern structures which are exposed by the first mask such that others of the second pattern structures remain on the layer of hard mask material, forming a second mask that covers a location where a line of the line/space pattern to be formed is to have a width that is greater than the widths of the second pattern structures, forming a hard mask by etching the hard mask material layer using the second mask and the remaining second pattern structures as an etch mask, and etching the substrate using the hard mask as an etch mask.