초록 |
The interfacial interactions for polystyrene-b-poly(2,2,2-trifluoroethyl acrylate) (PS-b-PTFEA) films were modulated to balance the dissimilar surface tensions between PS and PTFEA, where the Flory-Huggins interaction parameter (χ) of PS-b-PTFEA is above 0.23. A neutral homopolymer substrate and top coat materials are applied where a sub-10 nm perpendicular lamellar morphology is observed with simple thermal annealing process. The balanced interfacial interactions for the block copolymer (BCP) films are tuned by overlying neutral layers using the same monomer of the BCP with a maleic anhydride units. We also demonstrate GISAXS experiments to confirm the orientation of perpendicular lamellae thickness window, which the neutral property turns out to be compositionally asymmetric toward styrene units. Additionally, directed self-assembly (DSA) is conducted by electric field, resulting a long-range uniaxial alignments over 2-um scale. |