Study of the kinetics and mechanism of rapid self-assembly in block copolymer thin films during solvo-microwave annealing

dc.contributor.authorMokarian-Tabari, Parvaneh
dc.contributor.authorCummins, Cian
dc.contributor.authorRasappa, Sozaraj
dc.contributor.authorSimao, Claudia
dc.contributor.authorSotomayor Torres, Clivia M.
dc.contributor.authorHolmes, Justin D.
dc.contributor.authorMorris, Michael A.
dc.contributor.funderScience Foundation Irelanden
dc.contributor.funderEuropean Commissionen
dc.date.accessioned2016-02-10T18:05:30Z
dc.date.available2016-02-10T18:05:30Z
dc.date.issued2014-08-19
dc.date.updated2014-10-21T11:17:22Z
dc.description.abstractMicrowave annealing is an emerging technique for achieving ordered patterns of block copolymer films on substrates. Little is understood about the mechanisms of microphase separation during the microwave annealing process and how it promotes the microphase separation of the blocks. Here, we use controlled power microwave irradiation in the presence of tetrahydrofuran (THF) solvent, to achieve lateral microphase separation in high- lamellar-forming poly(styrene-b-lactic acid) PS-b-PLA. A highly ordered line pattern was formed within seconds on silicon, germanium and silicon on insulator (SOI) substrates. In-situ temperature measurement of the silicon substrate coupled to condition changes during "solvo-microwave" annealing allowed understanding of the processes to be attained. Our results suggest that the substrate has little effect on the ordering process and is essentially microwave transparent but rather, it is direct heating of the polar THF molecules that causes microphase separation. It is postulated that the rapid interaction of THF with microwaves and the resultant temperature increase to 55 degrees C within seconds causes an increase of the vapor pressure of the solvent from 19.8 to 70 kPa. This enriched vapor environment increases the plasticity of both PS and PLA chains and leads to the fast self-assembly kinetics. Comparing the patterns formed on silicon, germanium and silicon on insulator (SOI) and also an in situ temperature measurement of silicon in the oven confirms the significance of the solvent over the role of substrate heating during "solvo-microwave" annealing. Besides the short annealing time which has technological importance, the coherence length is on a micron scale and dewetting is not observed after annealing. The etched pattern (PLA was removed by an Ar/O-2 reactive ion etch) was transferred to the underlying silicon substrate fabricating sub-20 nm silicon nanowires over large areas demonstrating that the morphology is consistent both across and through the film.en
dc.description.sponsorshipScience Foundation Ireland (SFI CSET/CRANN); European Commission (LAMAND NMP FP7)en
dc.description.statusPeer revieweden
dc.description.versionSubmitted Versionen
dc.format.mimetypeapplication/pdfen
dc.identifier.citationMOKARIAN-TABARI, P., CUMMINS, C., RASAPPA, S., SIMAO, C., SOTOMAYOR TORRES, C. M., HOLMES, J. D. & MORRIS, M. A. 2014. Study of the Kinetics and Mechanism of Rapid Self-Assembly in Block Copolymer Thin Films during Solvo-Microwave Annealing. Langmuir, 30, 10728-10739. http://dx.doi.org/10.1021/la503137qen
dc.identifier.doi10.1021/la503137q
dc.identifier.endpage10739en
dc.identifier.issn0743-7463
dc.identifier.issued35en
dc.identifier.journaltitleLangmuiren
dc.identifier.startpage10728en
dc.identifier.urihttps://hdl.handle.net/10468/2281
dc.identifier.volume30en
dc.language.isoenen
dc.publisherAmerican Chemical Societyen
dc.relation.urihttp://pubs.acs.org/doi/abs/10.1021/la503137q
dc.rights© 2014 American Chemical Society. This document is the Submitted Manuscript version of a Published Work that appeared in final form in Langmuir, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/pdf/10.1021/la503137qen
dc.subjectPS-b-PMMAen
dc.subjectDiblock copolymersen
dc.subjectLow temperaturesen
dc.subjectPolystyreneen
dc.subjectOrientationen
dc.subjectPolylactideen
dc.subjectDiffusionen
dc.subjectSiliconen
dc.subjectArraysen
dc.titleStudy of the kinetics and mechanism of rapid self-assembly in block copolymer thin films during solvo-microwave annealingen
dc.typeArticle (peer-reviewed)en
Files
Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
PMT_StudySV2014.pdf
Size:
1.69 MB
Format:
Adobe Portable Document Format
Description:
Submitted Version
License bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
license.txt
Size:
2.71 KB
Format:
Item-specific license agreed upon to submission
Description: