Theoretical Study on Reactivity of Photoacid Generators for EUV Lithography

Abstract

We have investigated the reactivity of photoacid generators for extreme ultraviolet (EUV) exposure. Quantum chemical calculation was performed. As the secondary electrons from the polymer in a resist cause the reaction of the photoacid generator, the reactivity of the photoacid generator is determined as its electron affinity. We optimized the molecular structure of the photoacid generator and calculated the electron affinity of the photoacid generator. Through the calculation of the electron affinity and population analysis of added electrons, we found that incorporation of electron withdrawing group increases the reactivity of photoacid generators.