Monomer having fluorine-containing acetal or ketal structure, polymer thereof, and chemical-amplification-type resist composition as well as process for formation of pattern with use of the same

摘要

As a polymer exhibiting improved transparency which is suitable for a resist resin used in a chemical-amplification-type resist being applicable for photolithography using exposure light at 180 nm or shorter, this invention provides a polymer comprising a repeating unit resulting from polymerization of a monomer exhibiting a polymerization activity, wherein the monomer has a fluorine-containing acetal or ketal structure represented by general formula (1):; wherein R represents an atomic group containing a carbon-carbon double bond exhibiting polymerization activity; at least one of R¹ and R² is fluorinated alkyl group or fluorinated aryl group having 1 to 20 carbon atoms; and R³ represents a radical selected from the group consisting of hydrogen atom, alkyl group, alkoxy-substituted alkyl group, fluorinated alkyl group, aryl group, fluorinated aryl group, aralkyl group and fluorinated aralkyl group having 1 to 20 carbon atoms.