Abstract
Protons generated in chemically amplified resists drive pattern formation reactions such as acid catalytic deprotection reactions. Proton dynamics is controlled by the addition of base quenchers so that ultrafine patterns are obtained. However, the details of interaction between protons and base quenchers are still unclear. In this study, we investigated the reactions of protons with base quenchers in a model system of chemically amplified resists with a typical backbone polymer, poly(4-hydroxystyrene). We confirmed that an acid-base equilibrium was reached in the model system without elevating the temperature of the films. The proton affinities of resist ingredients give us a general estimation of protonation sites. When the proton affinities of resist ingredients are close to each other, we have to take into account acid-base equilibrium using pKa for the accurate prediction of protonation sites.