forming an etch film on a substrate;

forming a protection film on the etch film;

forming a hard mask layer on the protection film;

forming a plurality of first mask patterns characterized by a first pitch on the hard mask layer;

forming a plurality of second mask patterns, wherein each second mask pattern is disposed between two adjacent first mask patterns of the plurality of first mask patterns;

forming hard mask patterns exposing first portions of the protection film by etching the hard mask layer using the first and second mask patterns as an etch mask;

removing the first and second mask patterns;

exposing portions of the etch film by removing the first portions of the protection film; and,

forming a plurality of fine patterns characterized by a second pitch equal to half of the first pitch by etching the etch film using at least the hard mask patterns as an etch mask.