A statistical thermodynamic approach to model plasma reactors

Three different approaches were adopted to study the gas phase behavior of plasmas. The former is based on a detailed kinetic model, the second on the traditional thermodynamic equilibrium assumption and the latter derives fr om statistical thermodynamics. In particular, the extension of the statisti cal fragmentation approach, originally developed for photo-ionization syste ms, to plasma enhanced chemical vapor deposition reactors was considered fo r the first time. Among the different systems studied were hydrocarbon and chloro-hydrocarbon plasmas. The aim of the work was to develop a reliable s tatistical thermodynamic approach apt to study the chemical reactivity of p lasmas starting only from thermodynamic data. The enthalpies and entropies of formation of the considered compounds were either taken from the literat ure or calculated through quantum chemistry. Finally the predictions of the three approaches were compared with the;available literature data and the advantages and errors implicit in each approach were discussed.