Pulsed plasma polymerization of pentafluorostyrene: Synthesis of low dielectric constant films

Abstract

A variable duty cycle pulsed plasma was employed to synthesize polymeric films from pentafluorostyrene monomer. The physical properties of the resultant films are observed to vary in progressive fashion with changes in the plasma duty cycles employed during deposition, all other plasma variables remaining constant. The sequential variations in film compositions with plasma duty cycles were demonstrated spectroscopically (infrared and x-ray photoelectron spectroscopy) as well as by dielectric constant, thermal stability, and surface energy measurements. In the case of pentafluorostyrene, a trade off in dielectric constant and thermal stabilities is observed as the lower dielectric constant films exhibit poorer thermal stability. In particular, this study shows that the variable duty cycle pulsed plasma synthesis approach can be employed to adjust physical properties of films, particularly dielectric constants, in unusually controllable fashion.