| 초록 |
In this study, we demonstrate directed self-assembly (DSA) of block copolymers (BCPs) in thin films using soft grating patterns. By physically rubbing poly(tetrafluoro ethylene) (PTFE), the horizontally aligned PTFE grating patterns (pitch ~ 300 nm and amplitude ~ 15nm) are produced on flat Si substrates due to its low friction coefficient and high wear rate. Thin films of polystyrene-block-poly(methyl methacrylate) copolymers (PS-b-PMMA) and polystyrene-block-poly(methacrylate) copolymers (PS-b-PMA) are then spin-coated on the patterned substrates. By using either solvent-annealing or thermal annealing, the BCPs self-assembly is induced on large area. It is found that the lamellar nanostructures are aligned along the pitch of underlying PTFE grating patterns. The BCP ordering is also dramatically enhanced due to the grating patterns. For potential applications, the aligned lamellar nanostructures are successfully transferred to the Si wafer by RIE process. |
