A method for defining a length of a fin including forming a plurality of first slice walls on a mask material layer, which is provided over the fin, using a plurality of hard mask patterns, providing a plurality of fill mask patterns self-aligned with respect to the plurality of first slice walls to expose one or more select areas between one or more pairs of adjacent ones of the plurality of first slice walls, and providing a trim mask pattern including one or more openings and self-aligned with respect to the plurality of second slice walls to expose one or more of the plurality of first slice walls may be provided.