Study of the Reaction of Acid Generators with Epithermal and Thermalized Electrons

Ionizing radiation such as extreme ultraviolet (EUV) radiation and electron beams generates secondary electrons in resist materials. Acid generators are mainly decomposed by reaction with these electrons. The reaction of acid generators with solvated electrons has been well investigated. However, the reaction with electrons before solvation, in particular, during thermalization, has not been investigated because of measurement difficulties. Because the ejected electrons are not solvated in solid resist films, it is important to elucidate the reactions of acid generators with the electrons before solvation. The reactions before solvation are expected to give direct insight into the reactivity of acid generators with electrons in solid films. In this study, we investigated the reactivity of acid generators with electrons before solvation using picosecond pulse radiolysis. The dependence of reactivity on molecular structures was clarified in terms of C37 parameters.