On the E to H and H to E transition mechanisms in inductively coupled plasma

Abstract

Inductively coupled plasmas (ICP) exhibit two mode operations of capacitive coupling (E mode) and inductive coupling (H mode), and the density jump and hysteresis have been reported during the transition between these modes. In this study, the total power transferred to the plasma by capacitive and inductive coupling is calculated from Maxwell's equations and global model, and from this, conditions required for stable E and H mode operations are obtained. The E to H and the H to E transitions occur when the system reaches critical electron densities. Analytical criterion for stable H mode operation that the skin depth should be smaller than root 2/3R at low pressure, and 2/root 3(omega/nu)R at high pressure is derived from the calculation. The dependence of transition electron densities and powers of E to H and H to E transitions on the pressure and discharge dimension is also discussed.