Visible-light-sensitive photo-acid generator incorporating food dye for use in chemically amplified resists

Abstract

Diphenyliodonium4-(3-N,N-diethylamino-6-diethyliminium-9-xantenyl) -3-sulfonato-phenylsulfonate was designed and prepared. The diphenyliodonium salt with a food dye as a counter anion showed good thermal stability, and had a decomposition temperature of 201.1°C. From the results of our investigation, the mechanism of acid generation is considered to be intramolecular electron transfer from the excited dye moiety to the iodonium. The photosensitivities of the photopolymer with a tetrahydropyranyl protecting group were 2.09 and 0.84 J/cm2 at 488 nm and 514 nm, respectively. ©2005TAPJ.