New Photoacid Generators Designed for Advanced EUV Patterning

Chemically amplified resists (CAR) serve as a crucial element of the successful implementation of extreme ultra-violet lithography (EUVL) in high volume manufacturing (HVM). Advancing the use of CAR materials for cutting-edge printing modes necessitates a continued emphasis on improving lithographic performance. This includes enhancing resolution, reducing feature-roughness, and increasing sensitivity (RLS), while also mitigating stochastic defects. Our team focuses on material design approaches for improving CAR resist performance. In this report, we present new design of slow acid diffusion photoacid generator (PAGs). The PAGs were designed to have outstanding solubility in typical formulation solvents. These PAGs were used as additive in CAR and then evaluated under the KrF and EUV exposures. These new PAGs exhibits much slower acid diffusion compared to well-known PAG. Notably, this improvement also leads to the enhanced resist sensitivity, although it was not anticipated, while simultaneously maintaining or improving lithographic critical dimension uniformity (LCDU), along with the advantage of an overall lower Z-factor performance.