Atsuhiro Yamano

RF Glow Discharge and Ion Transport: Effects of Applied Frequency, Gas Pressure and Method of Power Coupling

Spatiotemporal structures in a parallel-plate RF glow discharge using argon plasmas have been simulated based on fluid approximation. For unchanged RF and DC bias components of voltage applied at an electrode, ion density, ion flux and mean electric power density increase as frequency f and gas pressure P become higher, whereas sheath length and its variation amplitude are inversely proportional to √f and √P. When two independent RF power supplies having identical frequency and applied voltage to each other are coupled to two electrodes, ion density and ion flux have their maximum values when the phase difference between the two RF power supplies is 180°. Energy and angular distributions of ions striking the electrode are also studied based on the Monte Carlo technique for the simulated parameters of the RF glow discharge. Since the ratio of sheath length to ion mean free path is proportional to √P/f, high-frequency operation under a low-pressure condition is preferable to achieve less attenuated, centered energy and less scattered angular distributions of ions.