Energy flux onto an RF magnetron surface

Abstract

The energy flux onto an RF magnetron electrode surface was measured by a nonperturbative calorimetric method in Ar, CF₄, C₂F₆, CHF₃ and C₃F₈ discharges. It was found that about 40% to 80% of the input RF power was dissipated on the magnetron electrode surface. The energy flux is 15% to 50% higher in argon than that in the fluorocarbons. When the sheath voltage is greater than 100 V, energy flux is mainly contribute by ion kinetic energy, and Q varies as n_i mod V_DC mod varies as (RF power)^1.2, where n_i is the ion density and V_DC is the DC potential of the capacitively coupled magnetron electrode. For the sheath voltage less than 100 V, radiation, electron-ion wall recombination, and neutral relaxation processes have to be considered. It is also found that the anomalous diffusion, presumably due to drift-type turbulence, affects the cross-field energy flux to the electrode surface.