Ultralow line edge roughness of hybrid multilayer Extreme ultraviolet resist with vertical molecular wire structure

Abstract

This study introduces an innovative extreme ultraviolet (EUV) resist featuring a vertically oriented molecular wire architecture, designed to achieve exceptionally low line edge roughness (LER). The resist is synthesized via molecular layer deposition, a gas-phase technique that allows precise monolayer-level control over thickness, ensuring excellent reproducibility, conformality, and uniformity. The hybrid multilayer resist is constructed through controlled ligand-exchange reactions between diethylzinc and 3-mercaptopropanol (3MP), which create vertically oriented molecular wires with widths below 1 nm. This innovative structure achieves an unprecedentedly low LER of 1.37 nm at a dose of 60 mJ/cm². EUV exposure induces unique cross-linking coordination bonds between the zinc atoms and the oxygen and sulfur atoms in 3MP without degassing, thereby enhancing EUV sensitivity. The combination of vertically oriented high-aspect-ratio molecular wires and effective lateral cross-linking significantly improves EUV sensitivity and robustness during etching. This pioneering hybrid multilayer EUV resist may satisfy the stringent requirements of advanced semiconductor manufacturing.