Global model studies of species composition and chemical reactions in inductively coupled HBr/Cl₂/Ar plasmas

Inductively coupled plasma (ICP) sources are effective for generating high-density plasma at low pressure and are widely used in etching processes. Among these, halogen-based plasma has become a significant research focus due to their flexible and tunable chemical etching path, high etching rate, and excellent etching anisotropy. In this study, HBr/Cl₂/Ar plasmas have been simulated using an independently developed global model of inductively coupled plasmas. The reliability of the model is verified through experimental measurement using a cut-off probe and comparisons with other simulation results. This study found that the density of Cl and H atoms, unlike Br atoms, exhibits a non-monotonic variation with pressure and Ar content. This is due to difference between the main production and loss mechanisms of these atoms. Additionally, the dissociation fraction curves of Br and Cl atoms exhibit an inflection point when adjusting the Cl₂ content. The study found that the positions of these inflection points are closely related to the molecular densities of HCl and BrCl.