Numerical analysis and experimental investigation of discharge characteristics in a ring dielectric line surface‐wave processing plasma apparatus

Abstract

SUMMARYDischarge characteristics in ring dielectric line surface-wave processing plasma (RDL-SWP) apparatus are studied both numerically and experimentally. To numerically simulate electromagnetic waves in SWP apparatus with a cylindrical discharge chamber such as RDL-SWP apparatus, a three-dimensional computer code is developed, employing Cartesian coordinates to allow simulation of both the plasma and rectangular waveguide connected to the chamber. The finite difference time domain (FDTD) method is the basis of the numerical code. Electron density and temperature profiles are measured experimentally in Ar plasma using a movable single probe and the optical emission patterns are studied. It is found that peaks in the electron density profiles coincide with intense optical emissions. For profiles across bulk plasmas with densities higher than cut-off, diffusion effects are found to be more dominant than localized plasma effects produced by surface waves. In particular, by comparison of numerical and experimental results, the applicability and limitations of a plasma model in which uniform electron density is assumed are evaluated.

Uniformity enhancement of a microwave surface-wave plasma by a field agitation

“…Furthermore, plasma light intensity is linearly proportional to ion density. [25][26][27] Since the ion density at the SWP near the quartz disk is higher than that of the bulk region by more than 10 times, the light intensity would surpass that from the bulk by at least 10 times, leading to the SWP being the dominant light source for the image. In this sense, it is reasonable to think the measurement results reflect the inhomogeneous distribution of the SWP.…”

Surface wave excited plasma CVD technologies for the synthesis of carbon nanomaterials

“…Plasma characteristics in a SWP will be introduced in detail to help understanding how to use and control a SWP as a plasma source for CVD applications. 4] Electric field distributions in plasmas for a volume wave mode and a surface wave mode [1].…”