Molecular design for the position-selective scission of polymer skeleton by ionizing radiation

Benzyl ester was found to be a functional group suitable for inducing position-selective scission of polymer skeletons by ionizing radiation. A molecule with benzyl ester on the skeleton captures a free electron generated by ionizing radiation, which then dissociates into a stable carboxylate anion and the benzyl radical, asR1COOCH(C6H5)R2+e−→R1COO−+CH(C6H5)R2The dissociation is induced by the excess electron in the antibonding orbital of the R1COO–CH(C6H5)R2 bond. A polymer with benzyl ester in the middle of the skeleton can be used as an electron beam and X-ray resist with high sensitivity and spatial resolution.