Computational Study on Dissociation Properties of C$_{\mathrm{4}}$F$_{\mathrm{6}}$ Molecules

Saturated or unsaturated perfluorocarbons(PFCs) have been used extensively in dry etching processes due to their relatively low global warming potential and their high CF$_{\mathrm{2}}$ radical levels in commercial plasma processes. Many experimental and theoretical studies of these species have been performed for useful information about physical and chemical properties of PFCs. Recently, it was reported that the $\omega $B97X-D/aVTZ method is strongly recommended as the best practical density functional theory(DFT) for rigorous and extensive studies of PFCs because this theoretical level shows the high performance and reliability especially for van der Waals interactions. Among various PFCs, this study focuses on C$_{\mathrm{4}}$F$_{\mathrm{6}}$ molecules including c-C$_{\mathrm{4}}$F$_{\mathrm{6}}$, 1,3-C$_{\mathrm{4}}$F$_{\mathrm{6}}$, and 2-C$_{\mathrm{4}}$F$_{\mathrm{6}}$ isomers. All the feasible isomerization and dissociation paths of C$_{\mathrm{4}}$F$_{\mathrm{6}}$ molecules were investigated mainly at the $\omega $B97X-D/aVTZ level. Their reaction rate constants were computed by using variational transition-state theory for a deep insight into C$_{\mathrm{4}}$F$_{\mathrm{6}}$'s reaction mechanism. Fates and roles of C$_{\mathrm{4}}$F$_{\mathrm{6}}$ molecules and their fragments in plasma phases could be explained based on our theoretical results and data.