Enhanced Lithography Performance with Imino/Imido Benzenesulfonate Photoacid Generator-Bound Polymer Resists

The inherent acid diffusion during post-exposure baking poses significant challenges in balancing resolution, line-edge roughness, and sensitivity (RLS), thereby constraining the performance of chemically amplified photoresists (CARs) in advanced lithography. This study introduces a novel series of alkene-functionalized imino/imido benzenesulfonate photoacid generators (PAGs), characterized by their solubility, thermal stability, and polymerization attributes. These derivatives can copolymerize with acrylates and methacrylates to form PAG-bound copolymers, integrating non-ionic PAG units and acid-cleavable bulky alicyclic substituents, facilitating their use as "single-component" resists devoid of additives. Upon exposure to electron beams or ultraviolet radiation, the sulfonamide esters undergo N─O bond scission, producing photoacids that catalyze the deprotection of acidolytic groups. Compared to PAG-blended systems, these PAG-bound systems curtail acid diffusion by generating long-chain sulfonic acids, while preserving high sensitivity. The formulated single-component CARs demonstrate superior resolution and roughness, achieving a minimum linewidth of 42 nm at an electron beam dose of 73 µC cm^{- 2}. This research provides a rational design for polymerizable imino/imido benzenesulfonate PAGs and single-component CARs, offering a viable solution to the RLS problem.