Creation and recombination of free radicals in fluorocarbon plasma polymers: An electron spin resonance study

Generation and recombination processes of plasma-induced radicals in plasma polymers are investigated using ESR, which provides valuable information about radicals in thin polymer films. The polymer films are prepared by means of r.f. plasma polymerization of c-C4F8. Radical numbers and densities of fluorocarbon plasma polymer coatings of different thicknesses are measured by extrapolating mixed-order recombination processes. The kinetics of radical generation in plasma polymer films is modeled using the results of the time-dependent radical decay studies. The life times, line-broadening effects, activation energies, and the temperature behavior of the radicals are discussed.