This invention relates to resins and photoresist compositions that comprise such resins. This invention includes new resins that comprise photoacid-labile deblocking groups, wherein the acid-labile moiety is substituted with one or more electron-withdrawing groups. Polymers of the invention are particularly useful as a resin binder component of chemically-amplified positive-acting resists that can be effectively imaged at short wavelengths such as sub-300 nm and sub-200 nm and preferably about 157 nm. In such short-wavelength imaging applications resins of the invention exhibit decreased absorbance of short wavelength exposure radiation, such as sub-170 nm radiation e.g. 157 nm.