Electron Kinetic and Electrodynamic Characteristics of ICP in Stochastic Heating Regime

Abstract

Electron kinetic and electrodynamic characteristics of ICP have been measured with improved diagnostic means over a wide range of argon pressure, discharge power and frequency. A large data base suitable for comparison with theory and computer experiment has been generated and some new features in ICP characteristics associated with non-local electron kinetics and electrodynamics have been revealed. The large population of low energy electrons (similarly to that in low pressure CCP), the frequency dependence of EEDF and electron temperature, the rf field phase velocity reversal, the phase bifurcation and the second current layer with localized regions of negative power absorption are found to take place over a wide range of gas pressure. These effects are most expressed at the lowest gas pressure of 0.3 mTorr and vanish at about 100 mTorr and higher gas pressures. These observations support the notion that the phenomena reported here can be attributed to near-collisionless electron motion typical for the anomalous skin effect. For the first time, we have demonstrated collisionless rf power absorption and negative power absorption in an ICP through direct measurements of the rf electric field and current in the plasma.