Gas heating by inductively coupled low-pressure chlorine process plasmas

Abstract

The mechanism of gas heating in low-pressure inductively coupled chlorine plasma is analyzed using a self-consistent two-dimensional axisymmetric fluid plasma model that is coupled with the compressible Navier-Stokes equations. For gas pressures of 10 and 20 mTorr and the discharge powers in the range 0.1 – 1.3 kW, the main reactions contributing to gas heating were the ion-ion recombination reactions and the quenching of electronically excited chlorine atoms. At the same time, the energy released by the electron impact dissociation reaction of molecular chlorine is negligible due to its high degree of dissociation within the plasma bulk. The comparison between the results of our simulations and the fitting equation proposed in the literature show qualitative agreement, although there is significant quantitative discrepancy.