CF2 surface reactivity during hot filament and plasma-enhanced chemical vapor deposition of fluorocarbon films

Relative gas-phase CF2 densities and CF2 surface reactivity were characterized during hot filament chemical vapor deposition (HF-CVD) of fluorocarbon (FC) films using our LIF-based imaging of radicals interacting with surfaces technique. CF2 density shows a clear dependence on the hexafluoropropylene oxide (HFPO) pressure and filament temperature. CF2 exhibits a low surface reactivity during deposition of CF2-rich FC films. Results are compared to measurements made during plasma-enhanced CVD (PECVD) of FC films. Mass spectrometry measurements reveal energetic ions with mean energies of 29–92 eV are produced in the PECVD source; these energetic ions account for the observed differences in scattering.