a method of forming a plurality of regularly spaced lithography features , the method including providing a self - assemblable block copolymer having first and second blocks in a plurality of trenches on a substrate , each trench including opposing side - walls and a base , with the side - walls having a width therebetween , wherein a first trench has a greater width than a second trench ; causing the self - assemblable block copolymer to self - assemble into an ordered layer in each trench , the layer having a first domain of the first block alternating with a second domain of the second block , wherein the first and second trenches have the same number of each respective domain ; and selectively removing the first domain to form regularly spaced rows of lithography features having the second domain along each trench , wherein the pitch of the features in the first trench is greater than the pitch of the features in the second trench .