Measurement of the total energy losses per electron-ion lost in various mixed gas inductively coupled plasmas

The total energy loss per electron-ion lost was measured at various gases and mixtures (Ar, He, N2, O2, Ar/N2, Ar/O2, He/N2, and He/O2) in the pressure range of 5–50 mTorr in an inductively coupled plasma. To measure electron temperatures and ion fluxes at a chamber wall, the floating harmonics method was used. The absorbed power was determined by measuring antenna resistances and currents. The total energy losses were obtained from the power balance equation of a global model. In the case of Ar mixture plasma with molecular gas, the total energy loss decreased with fractional Ar flow rate. He mixture plasma decreased more than the decrease in total energy loss of Ar mixture plasma. These experimental results were compared and were consistent with average collisional energy loss.