PATTERNING AND ETCHING OF AMORPHOUS TEFLON FILMS

Amorphous Teflon(R), deposited by spin-coating and thermal evaporation, has been studied as a low dielectric constant insulator for high performance interconnects. Since it is difficult to deposit a film on amorphous Teflon because of its inert chemical bonds, plasma etching and Zonyl FSN(R) fluorosurfactant are used to improve the adhesion of photoresist to amorphous Teflon. Plasma etching is shown to increase surface roughness and change chemical bonds of the amorphous Teflon, resulting in improved adhesion of metals and SiO2 to amorphous Teflon. While amorphous Teflon cannot be etched by wet chemicals, etching the films in Ar, O2, or CF4/O2 plasma is very effective.