2009 APS March Meeting
Volume 54, Number 1
Monday–Friday, March 16–20, 2009;
Pittsburgh, Pennsylvania
Session X20: Long Range Order in Polymer Structures and Morphologies
2:30 PM–5:30 PM,
Thursday, March 19, 2009
Room: 321
Sponsoring
Unit:
DPOLY
Chair: Sam Gido, University of Massachusetts
Abstract ID: BAPS.2009.MAR.X20.1
Abstract: X20.00001 : Long range ordering in block copolymer thin films
2:30 PM–3:06 PM
Preview Abstract
Abstract
Author:
Caroline Ross
(MIT)
Thin films of microphase separated block copolymers, which can
form patterns consisting of dense arrays of lines or dots, are
attractive materials for self-assembled nanoscale lithography.
The long range order of the block copolymer microdomains can be
controlled by the use of chemical or topographical patterns. In
this work, we discuss how Si-containing block copolymers,
polystyrene-b-polyferrocenyldimethylsilane (PS-PFS) and
polystyrene-b-polydimethylsiloxane (PS-PDMS), can be templated on
substrates patterned with posts or steps. In the case of 40 nm
period spherical morphology PS-PDMS, $<$20 nm diameter posts,
which are coated with a grafted layer of PDMS homopolymer, define
the locations of surrounding PDMS microdomains. The lattice
spacing and orientation of the templated PDMS microdomain array
can be predicted from the ratio between the post spacing and the
equilibrium microdomain spacing. PFS spheres, formed from
spherical-morphology PS-PFS, can be aligned within shallow
trenches to form a close-packed array with row spacing determined
by the trench width. We also show how 32 nm period cylindrical
morphology PS-PDMS can be templated using topographical features.
Templating using posts or linear substrate features gives arrays
of straight parallel cylinders with controllable period and
orientation, while templating in circular pits creates sharply
curved, concentric toroidal structures. The overall morphology
and period of the block copolymer microdomain arrays can be
varied by solvent annealing in mixed solvent vapors, for example
cylindrical-morphology PS-PDMS can form perforated lamellae by
annealing in toluene plus heptane. These results will be
discussed in the context of nanolithography, including examples
of pattern transfer to form metal, oxide and polymer functional
nanostructures.
Bita et al, Science 321 939 (2008); Jung et al, Nano Letts. 7
2046 (2007); 8 2975 (2008).
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2009.MAR.X20.1