Photoablation of polymers by laser beams is a practical process for via holes preparation in polymeric insulators. Excimer laser photochemistry of polymers is actively considered for microlithography. The ablation rate is dependent on the absorption coefficient. By addition of a dopant, photoetching rates of polymers can be increased significantly. In the present study the photoetching rates of poly(dimethyl glutarimide) and chlorinated poly(methylstyrene) are studied with pyrene as a dopant with 308 nm of XeCl excimer laser.