Polymerizable Nonionic Perfluorinated Photoacid Generators for High‐Resolution Lithography

Abstract Advanced photoresists must satisfy stringent sensitivity requirements while maintaining the ability to print ever‐shrinking critical dimensions. However, the unavoidable acid diffusion associated with chemically amplified photoresists has led to a trade‐off between resolution, line‐edge roughness, and sensitivity, which presents a significant challenge for high‐resolution lithography. To address this issue, a novel class of alkene‐functionalized nonionic perfluorinated photoacid generators (PAGs) is developed. These fluorine‐rich compounds significantly enhance the photochemical reactivity due to the introduction of abundant F‐elements, thereby improving sensitivity. Upon irradiation by ultraviolet light or electrons, they generate long‐chain perfluorinated sulfonic acids with large sizes and minimal diffusion ranges, effectively suppressing acid diffusion. Furthermore, by employing these polymerizable PAG monomers, PAG‐bound polymers are synthesized that are likely to achieve higher resolution by minimizing acid diffusion. Lithography performance demonstrated patterning of sub‐45 nm lines at an electron beam dose of 29 µC cm −2 . Overall, the developed perfluorinated PAGs and PAG‐bound polymer photoresists are promising candidates for achieving high‐sensitivity and high‐resolution nano‐patterning.