On the plasma parameters of a planar inductive oxygen discharge

Abstract

Langmuir probes and a quadrupole mass spectrometer were used to determine the plasma parameters of an oxygen plasma in a planar inductive discharge. The electron density, effective electron temperature, the dc plasma potential and the electron energy probability function (EEPF) in the discharge centre plane were investigated as functions of power, gas pressure and radial position. The ion energy distribution and relative density of positive ions at the radial sheath edge were investigated as functions of power and pressure. A volume-averaged global model of the electronegative oxygen discharge is developed. The model uses a power balance equation to account for energy deposited into the plasma and lost via collisions and particle flux. The particle densities are modelled via rate equations estimated from collision cross sections assuming Maxwellian electron energy distribution functions. The volume-averaged model is shown to predict the experimental trends over a range of process conditions.