Fundamental Studies of Acid-Breakable Resins for Chemical-Amplification Positive Resist Matrices

We have investigated acid-breakable (AB) resins for chemical-amplification positive resists. The AB resin was synthesized by a co-condensation reaction between an alkali-soluble polyphenol (4, 4′-[1-[4-[1-(4-Hydroxyphenyl)-1-methylethyl]phenyl]-ethylidene]bis phenol) and an aromatic multi-functional (tri-functional) vinylether compound. The AB resin did not dissolve in an aqueous base developer (TMAH: 2.38%), and it had a good margin for the polyphenol/vinylether feed ratio. Even for AB resins, with large differences in molecular weight, the AB-resin-based resist exhibited almost the same exposure characteristics. We also examined the relationship between the inhomogeneous distribution of the acid generator and the film structure of the AB-resin-based resist.