A method of forming a plurality of regularly spaced lithography features, e.g. contact holes, including: providing a trench on a substrate, the trench having opposing side-walls and a base, with the side-walls having a width therebetween, wherein the trench is formed by photolithography including exposing the substrate using off-axis illumination whereby a modulation is provided to the side-walls of the trench; providing a self-assemblable block copolymer having first and second blocks in the trench; causing the self-assemblable block copolymer to self-assemble into an ordered layer in the trench, the layer having first domains of the first block and second domains of the second block; and selectively removing the first domain to form at least one regularly spaced row of lithography features having the second domain along the trench.