Patent ID: 8361704

Claim:
A method for reducing tip-to-tip spacing between lines comprising: providing a substrate and a line structure in said substrate; forming a mask layer over said substrate; performing a lithographic process over said mask layer to create a trench opening of a width d in said mask layer, wherein said trench opening is above said line structure in said substrate and substantially perpendicular to said line structure; applying a layer of a block copolymer over said mask layer, wherein said block copolymer comprises at least first and second polymeric block components A and B respectively that are immiscible with each other; annealing said block copolymer layer to form a single unit polymer block of a width or a diameter w inside said trench opening, wherein w<d, and wherein said single unit polymer block comprises said polymeric block component B and is embedded in a polymeric matrix that comprises said first polymeric block component A; selectively removing said second polymeric block component B to form a single opening of a width or a diameter w in said polymeric matrix inside said trench opening; and performing an etch transfer process using said single opening as a mask to form a third opening in said line structure in said substrate, wherein said third opening cuts said line structure into two lines.