Abstract
This paper reports plane-type microwave resonator (MWR) probe for electron density measurements in reactive processing plasmas. The sheath effects were investigated by electromagnetic field analysis with FDTD simulation, and the calculated characteristics were confirmed experimentally. The FDTD simulation revealed that the sheath formed around the probe leads to underestimation of electron density, in comparison to the real density given as an initial condition in the simulation, which is caused by a decrease in the effective dielectric constant. An increase in a slit width of the probe antenna suppressed the density underestimation. Actually, as the slit width increased, the electron density measured by the MWR probe approached that obtained by a reference surface wave probe. Therefore, it is useful to enlarge the slit width for improvement of accuracy of the density measurement with the MWR probe.
