Synthesis of novel fluorinated norbornene derivatives for 157-nm application

We have synthesized various main-chain fluorinated polymers and studied their transparency and solubility. The main-chain fluorinated polymers were synthesized by co- or ter-polmerization of tetrafluoeoethylene (TFE) with cyclic monomers, especially TFE with newly synthesized norbornene derivatives. Transparency of the main-chain fluorinated polymers tended to be higher with higher fluorine contents. But exact absorbance of the main-chain fluorinated polymers by modifying the STUPID calculation. Solubility of the main-chain fluorinated polymers functionalized by hydroxyfluoroalkyl groups was also studied. We have developed a model to predict pKa of hydroxyfluoroalkyl groups incorporated in the norbornene derivatives, and studied correlation between pKa(OH) and solubility of the co-polymers of the hydroxyfluoroalkyl-functionalized norbornene derivatives with TFE. pKa Of the hydroxyfluoroalkyl groups were lower with higher fluorine contents, and solubility of the co-polymers tended to be higher with lower pKa of the hydroxyalkyl groups.