title: Control of self-assembly of lithographically patternable block copolymer films.
abstract: Poly(alpha-methylstyrene)-block-poly(4-hydroxystyrene) acts as both a lithographic deep UV photoresist and a self-assembling material, making it ideal for patterning simultaneously by both top-down and bottom-up fabrication methods. Solvent vapor annealing improves the quality of the self-assembled patterns in this material without compromising its ability to function as a photoresist. The choice of solvent used for annealing allows for control of the self-assembled pattern morphology. Annealing in a nonselective solvent (tetrahydrofuran) results in parallel orientation of cylindrical domains, while a selective solvent (acetone) leads to formation of a trapped spherical morphology. Finally, we have self-assembled both cylindrical and spherical phases within lithographically patterned features, demonstrating the ability to precisely control ordering. Observing the time evolution of switching from cylindrical to spherical morphology within these features provides clues to the mechanism of ordering by selective solvent.
authors.affiliation: Department of Materials Science and Engineering, Bard Hall, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Joan K
authors.initials: JK
authors.lastname: Bosworth
authors.forename: Marvin Y
authors.initials: MY
authors.lastname: Paik
authors.forename: Ricardo
authors.initials: R
authors.lastname: Ruiz
authors.forename: Evan L
authors.initials: EL
authors.lastname: Schwartz
authors.forename: Jenny Q
authors.initials: JQ
authors.lastname: Huang
authors.forename: Albert W
authors.initials: AW
authors.lastname: Ko
authors.forename: Detlef-M
authors.initials: DM
authors.lastname: Smilgies
authors.forename: Charles T
authors.initials: CT
authors.lastname: Black
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Ober
mesh_terms: D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008567:Membranes, Artificial; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D011137:Polystyrenes / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D008567:Membranes, Artificial; D011137:Polystyrenes