Directed self-assembly of linear and Janus-type bottlebrush block copolymers for enhanced EUV lithography pattern quality

BackgroundThe semiconductor industry strives to enhance lithography resolution in response to the demand for miniaturization and improved performance in electronic devices. The introduction of extreme ultraviolet (EUV) lithography, utilizing a short wavelength of 13.5 nm, has facilitated high-resolution patterning. However, the transition to EUV is constrained by limited photon availability at a given source power, resulting in photon shot noise that complicates the reduction of line edge roughness (LER) and defect removal.AimWe explore the potential for overcoming these challenges by combining directed self-assembly (DSA) of block copolymers (BCP) with EUV lithography and investigate methods for achieving high-quality patterning by modifying polymer chain architectures.ApproachWe performed Monte Carlo (MC) simulations with a coarse-grained model to compare the DSA behavior of linear block copolymers (LBCP) and Janus-type bottlebrush polymers (JBBP) on EUV-patterned guide templates with various roughness conditions.ResultsOur results demonstrate that DSA of linear block copolymers reduces LER and eliminates bridge defects.

Furthermore, Janus-type bottlebrush polymers, with densely grafted homopolymer side chains of different types, reduce pattern roughness compared with LBCP.ConclusionsThese findings demonstrate that JBBP architecture offers superior roughness reduction, whereas LBCP provides robust defect tolerance, establishing design guidelines for advanced EUV+ DSA patterning technologies.