Topcoat-Assisted Perpendicular and Straightly Parallel Coexisting Orientations of Block Copolymer Films

Jiyoung Jeong, Jeong Sook Ha, Sang Soo Lee, Jeong Gon Son

Research output: Contribution to journalArticle

13 Citations (Scopus)

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.

Original languageEnglish
Pages (from-to)1261-1266
Number of pages6
JournalMacromolecular Rapid Communications
Volume36
Issue number13
DOIs
Publication statusPublished - 2015 Jul 1

Keywords

  • block copolymer
  • dewetting
  • directional alignment
  • orientation
  • thin films

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

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