3 FLUID TRANSPORT MODELS BY PARTICLE-IN-CELL METHOD FOR RF GLOW-DISCHARGES

Three self-consistent fluid transport models, simulated by the particle-in-cell simulation method (PIC/FE), have been developed for parallel-plate RF glow discharges. The electron transport is modeled by the equilibrium single-moment and nonequilibrium two- and three-moment fluid equations. Two major ionization processes dominate the discharges; one is due to the secondary electrons (gamma discharge), the other is due to electrons between the bulk and the sheath (alpha discharge). In the equilibrium single-moment model, the alpha and gamma discharges are underestimated and the nonlocal gamma-discharge behavior is difficult to measure. On the other hand, the nonequilibrium three-moment model can clearly demonstrate the distinct alpha- and gamma-discharge effects similar to self-consistent Monte Carlo model results. Moreover, the three-moment model can describe the transitions of plasma density, sheath width, and bulk mean energy from the alpha regime to the gamma regime and verify the transition boundary between alpha and gamma regimes which are all consistent with experimental results. The results of the three-fluid models are presented, analyzed, and compared with each other in terms of the plasma density, electric field, average velocity, current density, mean energy, and ionization rate.