Controlled alignment of block copolymer with solvent annealing using top coating layer

초록

Self-assembly of blcok copolymers (BCPs) is attractive for many potential applications such as porous membranes, anti-reflective coating and electrical devices. Among them, polystryene-b-poly dimethylsiloxane(PS-b-PDMS) copolymers are widely used due to high etch selectivity from silicon containing PDMS block to oxygen plasma, and sub-10 nm patterns from high x parameter between two domains. However, PS-b-PDMS hardly presents perpendiular orientation because of huge difference of surface tension between PS and PDMS blocks. so that PDMS domain with low surface tension locates a the surface. We introduce here top coating layer on PS-b-PDMS which neutralizes interfacial energy between each copolymer blocks. As PS-b-PDMS undergoes phase separation with solvent annealing, for energy minimization, PS-b-PDMS constructs perpendicularly oriented nano-structure in a large area.