title: Topcoat-Assisted Perpendicular and Straightly Parallel Coexisting Orientations of Block Copolymer Films.
abstract: Highly ordered perpendicular orientation and straightly parallel orientation coexisting polystyrene-block-polydimethylsiloxane (PS-b-PDMS) cylindrical microdomains with 10 nm width can be realized by using polyvinyl acetate as a partially dewetted topcoat and solvent annealing with acetone vapor. During solvent annealing, the swelled topcoat begins to dewet and the dewetting rim sweeps the surface of the block copolymer films to align the cylindrical microdomains with the direction of dewetting propagation. However, the wetted region of the topcoat/PS-b-PDMS film forms with a perpendicular orientation due to reduced surface tension and sufficient concentration gradient in the solvent evaporation step. The orientational changes (perpendicular/straightly parallel orientation) in the dewetted/wetted area are also investigated according to the vapor pressure of solvent annealing. The degree of directionality of the swept PS-b-PDMS films according to the distance from the dewetting front, which is equivalent with time after sweeping, is examined. To control the direction of dewetting and complex structures within a specific area, an imprinting process is introduced to form topographical line-space patterns in the topcoat and perpendicular/parallel orientation of BCP patterns in the line-space patterns, respectively.
authors: Photo-Electronic Hybrids Research Center, Korea Institute of Science and Technology, 14 gil-5 Hwarangno, Seongbuk-gu, Seoul, 136-791, Republic of Korea.|KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 136-701, Republic of Korea.
authors: Jiyoung
authors: J
authors: Jeong
authors: KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 136-701, Republic of Korea.
authors: Jeong Sook
authors: JS
authors: Ha
authors: Photo-Electronic Hybrids Research Center, Korea Institute of Science and Technology, 14 gil-5 Hwarangno, Seongbuk-gu, Seoul, 136-791, Republic of Korea.|KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 136-701, Republic of Korea.
authors: Sang-Soo
authors: SS
authors: Lee
authors: Photo-Electronic Hybrids Research Center, Korea Institute of Science and Technology, 14 gil-5 Hwarangno, Seongbuk-gu, Seoul, 136-791, Republic of Korea.
authors: Jeong Gon
authors: JG
authors: Son
mesh_terms: D000096:Acetone / Q000737:chemistry; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D008567:Membranes, Artificial; D058105:Polymerization; D011137:Polystyrenes / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D013499:Surface Properties; D014835:Volatilization
chemical_list: D004129:Dimethylpolysiloxanes; D008567:Membranes, Artificial; D011137:Polystyrenes; D011145:Polyvinyls; D000096:Acetone; C013215:polyvinyl acetate; C013830:baysilon
keywords: block copolymer; dewetting; directional alignment; orientation; thin films