A radiation absorbing polymer is characterized by having a main chain copolymer containing recurring units of dicarboxylic acid or carboxylic anhydride group with an organic chromophore bonded to the carboxyl group through methylene or alkylene linkage group, where the organic chromophore is bonded to the carboxyl group by esterification reaction. Residual carboxyl groups of the radiation absorbing polymer can optionally be amidized and/or imidized with an aromatic compounds having a reactive amino group. When the photoresist is applied on the antireflective coating and is exposed by radiation such as deep ultraviolet radiation, a resist pattern with high resolving power is formed, which is not affected by standing wave upon manufacturing integrated circuit elements.