A method is disclosed for forming a row of mutually spaced lithography features on a substrate, such as contact electrodes for a NAND device. The method involves forming and/or using a narrow slot over the substrate defined between the edge of a hard mask layer and a side wall of a trench in a resist layer overlying the edge and the substrate. A self-assemblable block copolymer is deposited and ordered in the trench for use as a further resist for patterning the substrate along the slot. The method allows for a sub-resolution contact array to be formed using UV lithography by overlapping the trench with the hard mask edge to provide the narrow slot in which the contact electrodes may be formed.