Patent ID: 8518835

Claim:
A method of forming a pattern, comprising: providing a block copolymer composition across a surface of a semiconductor substrate; the semiconductor substrate comprising monocrystalline silicon; the block copolymer composition comprising subunits A and B; the A subunits having lengths designated as L A ; the B subunits having lengths designated as L B ; the block copolymer composition ultimately being used to form core structures spaced center-to-center by a distance of L 0 ; the core structures having an average center-to-interface distance of R; the lengths L B being distributed across a range defined by, ( L 0 2 - R ) ≤ L B ≤ ( 2 2 ⁢ L 0 - R ) ; said distribution comprising a count of molecules per each of the individual lengths L B across the range; at least 50% of the counts being within a factor of 10 6 of one another; inducing self-assembly within the block copolymer composition to form a first domain corresponding to a plurality of the core structures, and to form a second domain around the core structures; adjacent core structures of said plurality being spaced center-to-center by L 0 ; and removing one of the first and second domains selectively relative to the other to form a patterned mask over the semiconductor substrate.