title: Large-area nanosquare arrays from shear-aligned block copolymer thin films.
abstract: While block copolymer lithography has been broadly applied as a bottom-up patterning technique, only a few nanopattern symmetries, such as hexagonally packed dots or parallel stripes, can be produced by spontaneous self-assembly of simple diblock copolymers; even a simple square packing has heretofore required more intricate macromolecular architectures or nanoscale substrate prepatterning. In this study, we demonstrate that square, rectangular, and rhombic arrays can be created via shear-alignment of distinct layers of cylinder-forming block copolymers, coupled with cross-linking of the layers using ultraviolet light. Furthermore, these block copolymer arrays can in turn be used as templates to fabricate dense, substrate-supported arrays of nanostructures comprising a wide variety of elements: deep (>50 nm) nanowells, nanoposts, and thin metal nanodots (3 nm thick, 35 nm pitch) are all demonstrated.
authors.affiliation: Department of Chemical and Biological Engineering, Princeton University , Princeton, New Jersey 08544, United States.
authors.forename: So Youn
authors.initials: SY
authors.lastname: Kim
authors.forename: Adam
authors.initials: A
authors.lastname: Nunns
authors.forename: Jessica
authors.initials: J
authors.lastname: Gwyther
authors.forename: Raleigh L
authors.initials: RL
authors.lastname: Davis
authors.forename: Ian
authors.initials: I
authors.lastname: Manners
authors.forename: Paul M
authors.initials: PM
authors.lastname: Chaikin
authors.forename: Richard A
authors.initials: RA
authors.lastname: Register
keywords: Block copolymer lithography; metal dots; nanopatterning; square arrays