2-D analytic model for inductively coupled plasma sources. II. Effects of 2-D coupled damping and their applications

For pt.I see ibid., vol.23, no.1, p.65-73 (1995). In part I, we developed the electromagnetic model and analyzed the plasma kinetic behavior for the recently developed inductively coupled plasma sources (ICPS). The analytic forms demonstrated that the induced RF wave in ICPS is primarily dampened by a collisionless dissipation mechanism, In this paper, the 2-D coupled damping effect is further discussed. A criterion is given to describe the magnitude of coupled damping relative to collisions. The numerical integrals show that the coupled damping is obvious only as the RF phase velocity is close to plasma thermovelocity. The electron velocity distribution function was calculated for different cases, Also analyzed were the geometry and frequency effects. It was found that appropriately adjusting the reactor height and coil current frequency could strengthen the coupled damping effect so as to benefit extracting the energy from the induced RF wave to the plasmas