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 ∝ as n1 mod VDC mod varies as (RF power)1.2, where ni is the ion density and VDC 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. © 1988 IOP Publishing Ltd.