The surface chemical composition and atomic emission spectroscopy of F atoms and CF2 molecules involved in the
processing of Atmospheric Pressure Plasma Jet (APPJ) produced from CF4 precursor has been explored. The XPS
spectra illustrated that small amount of radicals including C-CFn and CF-CFn could be introduced onto the fused silica
surface during the CF4 plasma process, the fluorocarbon radicals were generated during CF4 plasma ionization.
Moreover, the relative concentrations of excited state species of F atoms and CF2 molecules, which play significant role
in remove and fluorocarbon radicals, were acquired for CF4 plasma. The densities of F atoms increased dramatically with
increasing applied RF power, whereas CF2 molecules decreased monotonically over the same power range, the
subsequent electron impacted decomposition of plasma species after CF4 precursor fragmentation. The spectrum of the F
atoms and CF2 molecules fallowed the same tendency with the increasing concentration of gas CF4, reaching the
maximum at the 20sccm and 15sccm respectively, and then the emission intensity of reactive atoms decreased with more
CF4 molecules participating. Addition certain amount O2 into CF4 plasma resulted in promoting CF4 dissociation, O2 can
easily react with the dissociation product of CF2 molecules, which inhibit the compound of the F atoms, so with the
increasing concentration of O2, the concentration of the CF2 molecules decreased and the emission intensities of F atoms
showed the maximum at the O2/CF4 ratio of 20%. These results have led to the development of a scheme that illustrates
the mechanisms of surface chemistry reaction and the affection of plasma parameters in CF4 plasma systems with respect
to F and CF2 gas-phase species.