Photoresists and associated processes for microlithography in the extreme, far, and near UV are disclosed. The photoresists in some embodiments comprise (a) a fluorine-containing copolymer comprising a repeat unit derived from at least one ethylenically unsaturated compound characterized in that at least one ethylenically unsaturated compound is polycyclic and at least one ethylenically unsaturated compound contains at least one fluorine atom covalently attached to an ethylenically unsaturated carbon atom; and (b) at least one photoactive component. In other embodiments, the photoresists comprise a fluorine-containing copolymer comprising a repeat unit derived from at least one polycyclic ethylenically unsaturated compound having at least one atom or group selected from the group consisting of fluorine atom, perfluoroalkyl group, and perfluoroalkoxy group, characterized in that the at least one atom or group is covalently attached to a carbon atom which is contained within a ring structure and separated from each ethylenically unsaturated carbon atom of the ethylenically unsaturated compound by at least one covalently attached carbon atom. The photoresists have high transparency in the extreme/far UV as well as the near UV, high plasma etch resistance, and are useful for microlithography in the extreme, far, and near ultraviolet (UV) region, particularly at wavelengths .ltoreq.365 nm. Novel fluorine-containing copolymers are also disclosed.