Correlation between C₃₇ Parameters and Acid Yields in Chemically Amplified Resists upon Exposure to 75 keV Electron Beam

The decomposition efficiency of acid generators upon exposure to ionizing radiation such as an electron beam is mainly determined by the reactivity of acid generators with thermalized electrons. The reactivity has been estimated using solvated electrons generated in solutions because there has been no method to directly observe the reaction with thermalized electrons generated in resist films. However, the reactivity estimated from the reaction with solvated electrons does not have sufficient accuracy to reproduce the difference between acid generators. In this study, we investigated the relationship between the acid yield and C 37 parameter of acid generators. The C 37 parameter was evaluated using tetrahydrofuran solution. The C 37 parameter has been believed to reflect the reaction of solutes with presolvated electrons generated in solutions. It was found that the C 37 parameter correlates with acid yields measured in resist films.