Patent ID: 8785559

Claim:
A method of forming a self-assembled block copolymer structure, comprising: preparing an azido-functionalized random poly(styrene-r-ethylene oxide) graft copolymer by: reacting a reaction mixture comprising p-chloromethylstyrene and styrene to form polymer chains comprising chloromethyl moieties and repeating units derived from p-chloromethylstyrene and styrene, wherein the reaction mixture comprises p-chloromethylstyrene in a molecular amount greater than a molecular amount of the styrene; reacting the polymer chains with one or more oligomers or polymers of poly(ethylene oxide) to form a graft copolymer comprising chloromethyl moieties, wherein the poly(ethylene oxide) has only one nucleophilic end; and reacting the graft copolymer comprising chloromethyl moieties with an azide compound to displace chlorine atoms of the chloromethyl moieties to form azidomethyl moieties on the graft copolymer; forming the azido-functionalized random poly(styrene-r-ethylene oxide) graft copolymer over at least a portion of a floor of a trench in a substrate to provide a trench having at least one portion of the floor bearing azido-functionalized random poly(styrene-r-ethylene oxide) graft copolymer and at least one portion of the floor exposing the substrate; forming a block copolymer material within the trench in the substrate; and annealing the block copolymer material to self-assemble the block copolymer material into first and second self-assembled domains of a first polymer block of the block copolymer material in a matrix of a second polymer block, the first self-assembled domains over the at least a portion of the floor of the trench bearing a crosslinked material of the azido-functionalized random poly(styrene-r-ethylene oxide) graft copolymer, the first self-assembled domains oriented perpendicular to the at least a portion of the floor of the trench bearing the crosslinked material of the azido-functionalized random poly(styrene-r-ethylene oxide) graft copolymer and parallel to sidewalk of the trench, the second self-assembled domains over the at least a portion of the floor of the trench exposing the substrate, the second self-assembled domains oriented parallel to the floor and sidewalls of the trench.