Theoretical study on the dissociation reactions of C4F6 molecules

Low-pressure fluorocarbon plasmas are widely used in microelectronics fabrication for a variety of surface modification purposes. In particular, fluorocarbon plasmas are used for the etching of dielectrics such as silicon dioxide and silicon nitride. Among the various fluorocarbons, this study focuses on C4F6 molecules (C4F6s) which are composed of hexafluorocyclobutene (c-C4F6), hexafluoro-1, 3-butadiene (1, 3-C4F6), and hexafluoro-2-butyne (2-C4F6). We have investigated the dissociation reactions of C4F6s, resulting in CF2, CF3, C2F3, and C3F3 fragments, by using the wB97X-D functional with various basis sets. In this presentation, the geometrical properties, energetics, and dissociation mechanisms of C4F6s will be suggested.