title: Directed self-assembly of block copolymer films on atomically-thin graphene chemical patterns.
abstract: Directed self-assembly of block copolymers is a scalable method to fabricate well-ordered patterns over the wafer scale with feature sizes below the resolution of conventional lithography. Typically, lithographically-defined prepatterns with varying chemical contrast are used to rationally guide the assembly of block copolymers. The directed self-assembly to obtain accurate registration and alignment is largely influenced by the assembly kinetics. Furthermore, a considerably broad processing window is favored for industrial manufacturing. Using an atomically-thin layer of graphene on germanium, after two simple processing steps, we create a novel chemical pattern to direct the assembly of polystyrene-block-poly(methyl methacrylate). Faster assembly kinetics are observed on graphene/germanium chemical patterns than on conventional chemical patterns based on polymer mats and brushes. This new chemical pattern allows for assembly on a wide range of guiding periods and along designed 90° bending structures. We also achieve density multiplication by a factor of 10, greatly enhancing the pattern resolution. The rapid assembly kinetics, minimal topography, and broad processing window demonstrate the advantages of inorganic chemical patterns composed of hard surfaces.
authors.affiliation: Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
authors.forename: Tzu-Hsuan
authors.initials: TH
authors.lastname: Chang
authors.affiliation: Institute for Molecular Engineering, University of Chicago, Illinois 60637, United States.
authors.forename: Shisheng
authors.initials: S
authors.lastname: Xiong
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Jacobberger
authors.affiliation: Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
authors.forename: Solomon
authors.initials: S
authors.lastname: Mikael
authors.affiliation: Institute for Molecular Engineering, University of Chicago, Illinois 60637, United States.
authors.forename: Hyo Seon
authors.initials: HS
authors.lastname: Suh
authors.affiliation: Institute for Molecular Engineering, University of Chicago, Illinois 60637, United States.|IBM Albany NanoTech, Albany, New York 12203, United States.
authors.forename: Chi-Chun
authors.initials: CC
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
authors.forename: Dalong
authors.initials: D
authors.lastname: Geng
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
authors.forename: Xudong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Arnold
authors.affiliation: Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
authors.forename: Zhenqiang
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Institute for Molecular Engineering, University of Chicago, Illinois 60637, United States.
authors.forename: Paul F
authors.initials: PF
authors.lastname: Nealey