Cyclic Solvent Annealing Improves Feature Orientation in Block Copolymer Thin Films

TitleCyclic Solvent Annealing Improves Feature Orientation in Block Copolymer Thin Films
Publication TypeJournal Article
Year of Publication2016
AuthorsParadiso SP, Delaney KT, García-Cervera CJ, Ceniceros HD, Fredrickson GH
JournalMacromolecules
Volume49
Issue5
Start Page1743
Pagination1743–1751
Date Published03/2016
ISSN0024-9297
Keywords21975, CNSI/MRL, CSC, Fredrickson, Garcia-Cervera, MRL, NSF, XSEDE
Abstract

Solvent vapor annealing is a promising, flexible platform for controlling the self-assembly of block copolymer thin films. However, the ability for static solvent annealing alone to provide sufficient bias to generate vertically oriented features is limited. Here, we use dynamical field theory simulations to investigate the morphology dynamics and capacity for pattern selection of a cyclic solvent annealing process. We find that the swell step selectively strains features oriented parallel to the substrate, reducing their stability with respect to disorder, while vertically oriented domains remain stable through the full cycle. This memory effect may be exploited to systematically improve feature orientation with wide operating margins and favorable kinetics compared to static solvent or cyclic thermal annealing. In aggregate, these results suggest a simple, robust method for orienting features in solvent annealed block copolymer films, potentially obviating the need for external fields while minimizing the total annealing time. Solvent vapor annealing is a promising, flexible platform for controlling the self-assembly of block copolymer thin films. However, the ability for static solvent annealing alone to provide sufficient bias to generate vertically oriented features is limited. Here, we use dynamical field theory simulations to investigate the morphology dynamics and capacity for pattern selection of a cyclic solvent annealing process. We find that the swell step selectively strains features oriented parallel to the substrate, reducing their stability with respect to disorder, while vertically oriented domains remain stable through the full cycle. This memory effect may be exploited to systematically improve feature orientation with wide operating margins and favorable kinetics compared to static solvent or cyclic thermal annealing. In aggregate, these results suggest a simple, robust method for orienting features in solvent annealed block copolymer films, potentially obviating the need for external fields while minimizing the total annealing time.

URLhttp://dx.doi.org/10.1021/acs.macromol.5b02107
DOI10.1021/acs.macromol.5b02107
Grant: 
CSC, MRL (DMR-1121053)