Orientation Control in Thin Films of a High-χ Block Copolymer with a Surface Active Embedded Neutral Layer

摘要: Directed self-assembly (DSA) of block copolymers (BCPs) is an attractive advanced patterning technology being considered for future integrated circuit manufacturing. By controlling interfacial interactions, self-assembled microdomains in thin films polystyrene-block-poly(methyl methacrylate), PS-b-PMMA, can be oriented perpendicular to surfaces form line/space or hole patterns. However, its relatively weak Flory interaction parameter, χ, limits capability pattern sub-10 nm features. Many BCPs with higher parameters are capable forming smaller features, but these “high-χ” typically have imbalance surface energy between the respective blocks that make it difficult achieve required orientation. To address this challenge, we devised a polymeric active additive mixed into BCP solution, referred as embedded neutral layer (ENL), which segregates top film during casting and annealing balances tensions a...