Molecular design of dissolution inhibitor in chemical amplification resist system by molecular orbital method : transparency and reactivities with protons

The molecular orbital (MO) method has been applied to study the transparency of any dissolution inhibitors in the deep-UV region and the reactivities of those molecules with protons derived from a photoacid generator in a chemical amplification resist system for excimer laser lithography. The results indicate that 1,3-bis(tert-butoxycarbonyloxy) benzene is the best dissolution inhibitor with respect to both the transparency and the reactivities among the five dissolution inhibitors studied, because it has small absorption peaks in the wavelength range longer than 215 nm and easily decomposes into the oxycarbonyloxyl compound and the tert-butyl group upon proton attack. The validity of the MO approach is confirmed by the experimental results.