电容耦合射频放电的电子加热

Electron heating, mechanisms of plasma generation, and electron dynamics in dif- ferent types of capacitively coupled radio frequency (CCRF) discharges relevant for industrial applications are investigated by a combination of di®erent experimen- tal diagnostics, simulations and models. Geometrically symmetric and asymmetric single frequency discharges operated at low pressures, geometrically symmetric dual frequency discharges operated at two substantially di®erent frequencies and two sim- ilar frequencies (fundamental and second harmonic with variable phase shift between the driving voltages) as well as hybrid capacitively/inductively coupled (CCP-ICP) RF discharges are studied. Electron heating is found to be strongly a®ected by phenomena characteristic for a certain discharge type, that do not occur in another. At low pressures the generation of highly energetic electron beams by the expand- ing sheath is observed. Such beams propagate through the entire plasma bulk and are re°ected at the opposing plasma boundaries, if the electron mean free path is long enough. An analytical model demonstrates that these beams lead to an en- hanced high energy tail of the electron energy distribution function and are, there- fore, closely related to stochastic heating 超快门宽增强型CCD相机