4-(tert-Butoxycarbonyloxy)benzylp-toluenesulfonates as acid amplifiers applicable to chemically amplified photoresists

Abstract

Aiming at the improvement of photosensitivity of photoimaging materials triggered by photoacid species, some 4-(tert-butoxycarbonyloxy)benzyl p-toluenesulfonates were synthesized as acid amplifiers, which generated p-toluenesulfonic acid autocatalytically in the presence of the acid in a non-linear manner. Among of the compounds tested, 4-(tert-butoxycarbonyloxy)-3-nitrobenzyl p-toluenesulfonate was superior for the present purpose because of its thermal stability in the absence of acid. When this compound was coupled with a chemically amplified photoresist system, photosensitivity was raised up to about 5 fold.