Analytical Investigation of Plasma and Electrode Potentials in a Diode Type RF (Radiofrequency) Discharge

摘要

Electrical potentials of a plasma and both electrodes in a diode type RF discharge are analytically obtained under the assumptions of quasistatic electric fields in an ion sheath, low gas pressure, charge neutrality of the plasma, and eta <<1 (eas is the ratio of electrode areas). The dependence of dV sub p D/dU sub p (V sub p D and U sub p are the DC part of the plasma potential and the potential difference between the plasma and the RF power electrode, respectively) on eta is, then, compared with experimental results. The following conclusions are found: 1. The plasma potential does not necessarily have a simple harmonic form, even if the supplied RF power has that form. 2. The DC parts of the plasma potential and the RF power electrode potential change depending on the waveform of the supplied RF power, even if the RF amplitude and eta are kept constant. 3. -dV sub p D/dU sub p depends quadratically on eta, with a proportionality constant K which depends on the waveform of the supplied Rf power. Keywords: Plasma etching; Potential models; Reprints.