I. R. Jones and I. M. El-Fayoumi

Department of Physics, Flinders University
G.P.O.Box 2100, Adelaide, 5001 South Australia
Ieuan.Jones@flinders.edu.au

The physics of inductively coupled RF discharges is discussed by reference to the behaviour of a discharge which is produced within a planar induction coil reactor coupled to an RF generator via a simple series tuning circuit. Two topics are discussed in detail:

1. The connection between, on the one hand, the parameters of the generated plasma (electron number density, effective electron collision frequency) and, on the other, the impedance of the planar induction coil, measured in the presence of plasma. The connection is made via an electromagnetic theory [1] which has been developed to describe the operation of this type of plasma reactor. It accounts for inductive coupling to the plasma as well as any capacitive coupling which may be present.

2. The hysteresis in the E- to H-mode transitions which are observed to occur in ICP reactors. The phenomenology of these transitions is described and a convincing theoretical explanation, based on the electromagnetic theory mentioned above and capable of describing all the experimental observations, is presented.

A third important topic, namely, the interaction between the coupling circuit and the generated plasma is briefly touched upon. However, this subject is treated more fully in a companion paper presented at this conference by El-Fayoumi and Jones.

[1] I. M. El-Fayoumi and I. R. Jones, "Theoretical and experimental investigations of the electromagnetic field within a planar coil, inductively coupled RF plasma source" Accepted for publication in Plasma Sources Science and Technology (1998).