Ion and electron energy analysis at a surface in an RF discharge

Abstract

A retarding field analyser has been used to examine ion and electron energies at the grounded electrode of a capacitively coupled RF discharge in argon. The onset of collisional scattering of the ion distribution was observed at 0.05 mbar. A Tonks-Langmuir-type model has been used to generate a theoretical collision-free energy distribution which compares well with results at low pressure. The energies of electrons incident on the electrode were not consistent with the high-energy tail of a simple Maxwellian distribution in the plasma, and are better modelled by a two-temperature distribution.