Metal-Catalyzed Addition Polymers for 157 nm Resist Applications. Synthesis and Polymerization of Partially Fluorinated, Ester-Functionalized Tricyclo[4.2.1.0_(2,5)]non-7-enes

Abstract

Fluorinated tricyclo[4.2.1.0^(2,5)]non-7-ene-3-carboxylic acid esters are shown to undergo metal-catalyzed addition polymerization. The resulting homopolymers are transparent at 157 nm and demonstrate the utility of these monomers in development of photoresists for 157 nm lithography. Fluorinated tricyclononene (TCN) structures with ester substituents exhibit up to 3 orders of magnitude more transparency at 157 nm than conventional ester-functionalized norbornene structures as determined by gas-phase vacuum-ultraviolet spectroscopy and variable angle spectroscopic ellipsometry. Unlike their fluorinated norbornene counterparts, the fluorinated, ester-functionalized TCN monomers successfully undergo transition-metal-catalyzed addition polymerization to produce polymers with high glass transition temperatures and the etch resistance required for photolithographic resist materials applications. The potential use of fluorinated TCN structures for 157 nm photoresists is demonstrated through the synthesis and characterization of TCN monomers and polymers.