| abstract |
PROBLEM TO BE SOLVED: To have high transparency to radiation, excellent basic characteristics as a resist such as sensitivity, resolution, pattern shape, etc., to achieve both high dry etching resistance and high adhesion to a substrate, and to be a resist. The present invention provides a radiation-sensitive resin composition having excellent developability and storage stability, particularly a copolymer useful as a resin component in the radiation-sensitive resin composition. SOLUTION: The copolymer comprises a repeating unit derived from a monomer represented by 1-ethylcyclopentyl ester, 2-ethyladamantan-2-yl ester or the like of a carboxyl group-containing norbornene-based compound, and 2 (5H) -A copolymer having a repeating unit derived from a lactone monomer represented by furanone or a derivative thereof, wherein the total content of the former repeating unit exceeds 30 mol% of all the repeating units. The radiation-sensitive resin composition contains the copolymer and a radiation-sensitive acid generator. |