title: Control of the microdomain orientation in block copolymer thin films with homopolymers for lithographic application.
abstract: Block copolymer lithography is a promising method for fabricating periodical nanopatterns of less than 20 nm by self-assembly and can be applicable for fabricating patterned magnetic media with a recording density over 1 Tb/in.2. We found a simple technique to control the orientation of cylindrical microdomains in thin films. Simply by mixing polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) diblock copolymers with the homopolymer (PS or PMMA) of the major component, we could align the cylindrical microdomains perpendicular to the film surface. The added homopolymer induces conformational entropic relaxation of the block chains in microdomain space and stabilizes the perpendicular orientation of hexagonally packed cylindrical microdomains. Thus formed perpendicular cylinders can be readily aligned in a regular array with a grating substrate.
authors.affiliation: Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Kitano
authors.forename: Satoshi
authors.initials: S
authors.lastname: Akasaka
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Inoue
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Mikihito
authors.initials: M
authors.lastname: Takenaka
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yoshida
authors.forename: Hideki
authors.initials: H
authors.lastname: Nagano