| 초록 |
Achieving sub-10 nm high-aspect-ratio patterns from block copolymer(BCP) self-assembly requires both a high interaction parameter and a perpendicular orientation of microdomains. However, these conditions are quite difficult to achieve simultaneously because the blocks in a high-χ copolymer typically have very different surface energies, favoring in-plane microdomain orientations. We realize a fully perpendicular orientation of a high-χ BCP, PS-b-PDMS, using partially hydrolyzed polyvinyl alcohol top coat with a solvent annealing process, despite the large surface energy differences between PS and PDMS. The top coat on the block copolymer films under a solvent vapor atmosphere not only significantly reduces the interfacial energy difference but also provides sufficient solvent concentration gradient and appropriate solvent evaporation rates. We also use the top coats as a dewetting-induced shearing material for the laterally aligned BCP patterns during the solvent annealing. |
