Production of Volume Wave Plasma with Internally Mounted Cylindrical Planar Microwave Launcher and Two-Dimensional Field Analysis Using Finite Difference Time Domain Method

摘要

In this paper, we presented experimental results on the production of volume wave plasma (VWP) using an internally mounted cylindrical planar microwave launcher, for application to novel plasma processings, such as inner wall coating, impurity-free etching or internal sterilization of medical instruments using VWP. It was demonstrated that the ellipsoidal VWP is produced in front of a microwave launcher in He or Ar gas atmosphere. Numerical analyses of microwave fields radiated from a planar launcher have been carried out using the two-dimensional finite difference time domain (FDTD) method to determine the mechanism of VWP production in middle of the chamber. It was shown that the calculation results showed fairly good agreements with the experimental results measured using a dipole antenna probe. The spatial distributions of plasma density and the temperature of VWP were also measured using a double probe. It was found that the electron density is comparable to or slightly less than cutoff density of 7.4 x 10~(10) cm~(-3) corresponding to the microwave frequency of f_m = 2.45 GHz, and that the electron temperature is approximately 6 eV at the plasma center.