Polymerization initiator effects on fluoropolymers for 157-nm single-layer resists
Main-chain fluorinated or tetrafluoroethylene-based resins, including functional norbornene derivatives, were synthesized and the effects of the polymerization initiators on the resin properties, such as transparency at 157 nm, solubility in a standard alkaline developer and lithographic performance were studied. High transparency was obtained by the polymerization mechanism forming the end-capping group following decarboxylation. It was also confirmed that the monocyclic component improves the dry-etch resistance and that fluorination at the terminal groups improves the alkaline solubility.
initiator fluoropolymer 157-nm lithography resist materials