Confinement of Diblock Copolymer Thin Films Between Two Neutral Surfaces: Controlling Domain Orientation
Abstract
Thin P(dS-b-MMA) diblock copolymer films were confined between two P(S-r-MMA) random copolymer monolayers having a styrene fraction of 0.58. At this composition the interactions of the S and MMA blocks with the substrate are balanced, making the surfaces effectively neutral. Hydroxy terminated random copolymers were end grafted to silicon substrates providing uniform coverage of the substrate. Diblock copolymer films were cast on the end grafted random copolymer and a thin layer of random copolymer having a small perfluoro end group, which effectively anchors the random copolymer to the air/polymer interface due to its low surface energy, were subsequently cast on the diblock copolymer film. Upon annealing, the random copolymer monolayers strongly induced a lamellar orientation normal to the substrate and surface interfaces since the preferential wetting of each of the blocks at both interfaces was eliminated. Small angle neutron scattering, neutron reflectivity, and a novel depth profiling technique were used to elucidate the orientation of the morphology in the diblock copolymer thin film.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1998
- Bibcode:
- 1998APS..MAR.Y1113H