Characteristics of VHF excited hydrogen plasmas using a ladder-shaped electrode

A VHF excited hydrogen plasma was produced with a ladder-shaped electrode w hose excitation frequency ranged up to 100 MHz for gas pressures of 40-200 mTorr and the plasma parameters were measured with a Langmuir probe. When t he excitation frequency was increased, the electron density increased and t he electron temperature decreased. The pressure dependence of the electron temperature at excitation frequencies of 65 and 100 MHz was different from the usual relationship: the electron temperature tended to increase with in creasing pressure. (C) 2001 Elsevier Science B.V. All rights reserved.