A composition used to form an
acid sensitive +E,uns a+EE nti+E,uns r+EE eflective +E,uns c+EE oating (ARC) includes a
water soluble resin and a cross-
linker.
Radiation adsorptive components may be provided as part of the resin or, more preferably, as a separate dye. The composition may be applied on a substrate as a
radiation adsorbing layer and additionally cross-linked to form an
acid sensitive,
water insoluble ARC on which a +E,uns p+EE hoto+E,uns p+EE atterning +E,uns r+EE esist (PPR) layer may be formed. Being
acid sensitive, selected portions of an ARC formed from the composition may be removed by a suitable reversal of the cross-linking followed by a develop step, preferably with an aqueous developer, more preferably de-ionized water. The
water soluble resin is preferably hydroxystyrene-sulfonated
styrene copolymer, poly(2-isopropenyl-2-
oxazoline), or poly(
acrylic acid), the cross-
linker is preferably an
acetal diacid or a
water soluble divinyl
ether, and the dye is preferably 9-
anthracene methanol or a
squaric acid derivative. If a suitable +E,uns p+EE hoto+E,uns a+EE cid +E,uns g+EE enerator (PAG) is included then an ARC formed from such components may exhibit a
photosensitivity similar to or even lower than that of the overlying PPR. The
photosensitivity is preferably less than about 900 mJ / cm2, more preferably 100 mJ / cm2 or less.