In-situ measurement method of sheath capacitance in plasmas

In-situ measurement method of sheath capacitance was studied. To measure the sheath capacitance, small dual frequency sinusoidal voltage signals ($\sim$1V) are applied to floating planar probe. The sheath circuit model and capacitance of the dielectric deposition film on the probe are considered in our measurement. The experiment was performed at various discharge conditions and our results are in good agreements with other studies. This study can be helpful for plasma monitoring in industrial processing.