Comparison of model and experiment for Ar, Ar/O₂ and Ar/O ₂/Cl₂ inductively coupled plasmas

Comparisons of fluid model predictions with various measurements in an inductively coupled plasma are reported. The gas chemistries used include pure Ar, mixtures of Ar and O₂ and mixtures of Ar, O₂ and Cl₂ for pressures ranging from 10 to 80 mTorr and plasma densities ranging from ∼10¹⁰-10¹¹ cm^-3. Measurements of electron density, electron energy probability function, positive ion composition and wall flux and neutral radical concentration at the chamber wall are reported and compared with corresponding model predictions. The model treats electrons, ions and neutrals as fluids, under the assumption of quasineutrality. Power into electrons is from inductive coupling from an external coil and capacitive coupling is neglected. The non-isothermal, multicomponent reacting flow equations with jump boundary conditions are used to describe neutrals and are solved iteratively with the plasma and electromagnetic equations until a steady solution is found. Radical and ion composition predictions are shown to be in reasonable agreement for Ar and Ar/O₂ plasmas, but the corresponding predictions in mixtures of Ar, O₂ and Cl₂ are in only partial agreement with measurements, implying that the chemical reaction database for this chemistry requires further work.