Analysis of Deprotection Activation Energy of Dissolution Inhibitors in Three-Component Chemically Amplified Novolac-based Resists (2)

We have developed a three-component novolac-based resist with chemically amplified mechanism consisting of a novolac resin, a photoacid generator (PAG), and a dissolution inhibitor (DI). Factors that affect the sensitivity of the resist include the transmittance of the resist film, the degradability of the PAG, the dissolution inhibitory ability and deprotection reactivity of the DI, and the dissolution acceleration ability after the deprotection reaction. In this study, using DIs with different molecular skeletons and same tBoc groups, we evaluated the sensitivity of resist and the activation energy of the deprotection reaction. Activation energies were calculated by substituting the reaction rate constants obtained from Fourier transform infrared (FT-IR) spectra into the Arrhenius equation. The sensitivity of the resist varied depending on the structure of the DI. Therefore, it was expected that the activation energy for the deprotection reaction of the tBoc group will differ depending on the type of DI. However, no clear differences in activation energy were found. Therefore, it was clarified that the activation energy of the deprotection reaction did not affect the sensitivity of the photoresist for DIs with the same protecting group but different molecular skeleton.