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Title: Through-Thickness Vertically Ordered Lamellar Block Copolymer Thin Films on Unmodified Quartz with Cold Zone Annealing [Thru-Thickness Vertically Ordered Lamellar Block Copolymer Thin Films on Unmodified Quartz with Cold Zone Annealing]

Here, template-free directed self-assembly of ultrathin (~10’s nm) lamellar block copolymer (l-BCP) films of high-interfacial area into vertically oriented nanodomains holds much technological relevance for fabrication of next-generation devices from nanoelectronics to nanomembranes due to domain interconnectivity and high interfacial area. We report for the first time, the formation of full thru-thickness vertically oriented lamellar domains in 100 nm thin polystyrene- block-poly(methyl methacrylate) (PS- b-PMMA) films on quartz substrate, achieved without any PMMA-block wetting layer formation, quartz surface modification (templating chemical, topographical) or system modifications (added surfactant, top-layer coat). Vertical ordering of l-BCPs results from the coupling between a molecular and a macroscopic phenomenon. A molecular relaxation induced vertical l-BCP ordering occurs under a transient macroscopic vertical strain field, imposed by a high film thermal expansion rate under sharp thermal gradient cold zone annealing (CZA-S). The parametric window for vertical ordering is quantified via a coupling constant, C (= vT), whose range is established in terms of a thermal gradient (∇ T) above a threshold value, and an optimal dynamic sample sweep rate ( v ~ d/τ), where τ is the l-BCP’s longest molecular relaxation time and d is the T g,heat- T g,cool distance. Real-time CZA-S morphology evolutionmore » of vertically oriented l-BCP tracked along ∇ T using in-situ Grazing Incidence Small Angle X-ray Scattering exhibited an initial formation phase of vertical lamellae, a polygrain structure formation stage, and a grain coarsening phase to fully vertically ordered l-BCP morphology development. CZA-S is a roll-to-roll manufacturing method, rendering this template-free thru-thickness vertical ordering of l-BCP films highly attractive and industrially relevant.« less
ORCiD logo [1] ; ORCiD logo [1] ;  [2] ; ORCiD logo [3] ;  [1] ; ORCiD logo [1]
  1. Univ. of Akron, Akron, OH (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Nano Letters
Additional Journal Information:
Journal Volume: 17; Journal Issue: 12; Journal ID: ISSN 1530-6984
American Chemical Society
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
National Science Foundation (NSF); USDOE Office of Science (SC)
Country of Publication:
United States
36 MATERIALS SCIENCE; block copolymer; Cold zone annealing; in situ; vertical lamellae
OSTI Identifier: