Abstract
The discharge characteristics of a ring dielectric line surface wave processing plasma (RDL-SWP) apparatus have been studied on the basis of numerical simulations and experimental measurements. For the simulation of an electromagnetic wave in the RDL-SWP, the three-dimensional computer code has been developed for a cylindrical plasma chamber configuration with the Cartesian coordinates that facilitate the simulation in a rectangular wave guide placed on the chamber. The finite difference time domain (FDTD) method is used in this code to calculate Maxwell equations. Experimentally, for Ar gas the distributions of electron density and electron temperature were measured using a movable single probe and the optical emission patterns were observed. It was found that the peak points of the distributions of the electron density are nearly the same points where the optical intense emission takes place. For the distributions of the bulk plasma with the density higher than the cut-off density, the effect of the diffusion seems to be more dominant than the localization of surface plasma produced by the surface wave. By the comparison between the results of simulation and those of experiments, the applicability and the limitation of the plasma model with a fixed uniform electron density is evaluated.
