This work reports the influence of gas mixing ratio on the Cl-2/Ar, Cl-2/He, and Cl-2/N-2 plasma parameters, steady-state densities, and fluxes of active species in the planar inductively coupled plasma reactor. The investigation combined plasma diagnostics by Langmuir probes and quadrupole mass spectroscopy with a global (zero-dimensional) plasma model. It was shown that the dilution of Cl-2 by any additive gas results in a noticeable change in both the electron temperature and density, as well as provides the acceleration in the electron impact dissociation kinetics of Cl-2 molecules. No qualitative differences for the given three systems in regard to relative changes in active species densities and model-predicted etch rate behaviors were obtained. (C) 2008 The Electrochemical Society. [DOI: 10.1149/1.2993160] All rights reserved.