O atom kinetics in RF CCP oxygen plasma at increased pressures*

In this study, the 80 MHz symmetric CCP discharge in quartz tube was used as a source of pure O$_{2}$ plasma of increased pressures (10 to 100 Torr). This research is mainly focused on the balance of O atoms that is governed by processes of O$_{2}$ dissociation and O atom loss. The use of time-resolved actinometry technique in the modulated discharge allowed experimentally determining dissociation rate constant k$_{diss}^{O2}$ and atom loss frequency \gamma$_{loss}^{O}$. The O atom loss is connected with surface recombination at lower pressure and volume reactions at higher pressure. The variation of plasma parameters allowed varying gas temperature from ~500 K up to 1800 K and this allowed to study the O atom generation and loss mechanisms in a wide range of gas conditions. The behavior of k$_{diss}^{O2}$ at low E/N and the role of ozone in \gamma$_{loss}^{O}$ is discussed in detail.