Comprehensive ion-molecule reactive collision model for processing plasmas

The ion-molecule collision model for endothermic reactions created by Denpoh and Nanbu, which is the so-called “Denpoh–Nanbu theory (DNT),” has been extended to exothermic reactions. In addition to short-range charge exchanges between ions and molecules, a long-range charge exchange has been incorporated into the extended theory named “DNT+” in this work. Although, even today, there still is a lack of ion-molecule collision data required as fundamental input to plasma simulations for processing plasmas, DNT+ can provide a comprehensive cross section data set of ion-molecule collisions, including elastic, both endothermic and exothermic reactions, and short- and long-range charge exchanges, as well as other inelastic collisions. The cross sections for Ar+-CF4 and H2+-H2 collisions obtained using DNT+ agree well with data from the literature. Therefore, DNT+ could be widely used, not only for plasma simulation but also as a tool to easily generate preliminary data prior to experiments, especially when ion-molecule cross sections are not available.