Theoretical study of deprotonation of polymer radical cation for EUV Resist

摘要

We studied the deprotonation of polymer radical cation for extreme ultraviolet (EUV) resist. Quantum chemical calculation was performed. Upon EUV exposure to the polymer in resist, the ionization of the polymer occurs and the secondary electrons generate. After the ionization, the radical cations on the polymer generated by ionization are deprotonated. Protonated polymer reacts with the anion part of photoacid generator, which was reacted with the secondary electrons. As the results, the photoacid generates. For the sensitivity of resist, we so far theoretically clarified the importance of the ionization of polymer and the electron affinity of photoacid generator. In this paper, the deprotonation of polymer radical cation was investigated. The styrene polymers and acryl polymers with various substituent groups were compared. It was found that the phenol group of styrene polymer and hydroxyadamantane group of acryl polymer is preferable proton source, respectively.