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In this paper, recent advances in the physics of low pressure inductively coupled plasmas (ICPs) are reviewed where the interaction of an electromagnetic field with electrons is governed by electron thermal motion rather than electron–atom collisions. Direct measurement of the rf electric field and rf current density in the plasma made it possible to distinguish between collisional and stochastic (collisionless) electron heating. Several new phenomena such as a wave phase bifurcation, phase velocity reversal, a second current layer and negative power absorption have been found and interpreted in terms of non-local electrodynamics. Nonlinear effects induced by the rf Lorentz force such as nonlinear plasma polarization and second harmonic currents, as well as modification of the spatial distribution of the plasma caused by ponderomotive forces have been demonstrated in ICP under discharge conditions typical for industrial applications.

A mathematical analysis is given for a self-consistent dynamic model for rf sheaths in the frequency range between the ion and electron plasma frequencies for arbitrary collision parameters and arbitrary rf sheath voltages. Based on this analysis, an algorithm is developed to solve the problem numerically in its full generality. Using the method that is developed, it is found that the rf conductivity current causes an asymmetrical behavior of the plasma-sheath interface and of the sheath characteristics, but has little effect on the rf discharge current/voltage characteristics. Copyright 1994, 1999 Academic Press