Rapid and Cyclable Morphology Transition of High‑χ Block Copolymers via Solvent Vapor-Immersion Annealing for Nanoscale Lithography

The self-assembly of block copolymers (BCPs) has attracted considerable attention because it can effectively generate highly ordered nanostructures through a simple and cost-effective process. However, in BCP annealing systems, there remain several challenges and issues that must be resolved to achieve more rapid and tunable pattern formation of BCPs with a high Flory–Huggins parameter (χ) for next-generation lithography applications. Here, we introduce a useful annealing technique to induce a rapid morphological transition of sphere-forming poly­(styrene-b-dimethylsiloxane) (PS-b-PDMS) BCPs by employing multistep solvent vapor annealing (MSVA) and a combined annealing process of solvent vapor annealing (SVA) and immersion annealing (IA). We successfully obtained well-ordered sub-20 nm line, dot, core–shell dot, and core–shell line structures with a short annealing time (