Insulated modulation probe method for monitoring RF plasmas

In the measurement of RF plasma by the insulated pulse probe method, by applying a sinusoidal voltage (angular frequency p) to the probe instead of the pulse voltage, the RF component (angular frequency omega) in the probe current is modulated by the probe voltage. This modulation is a combination of both amplitude modulation and phase modulation, By analyzing the amplitude and phase angle of the upper and lower sidebands (omega + p, omega - p) that are derived by the modulation, the essential parameters of the RF plasma, such as the electron temperature, plasma density, time-averaged sheath voltage and amplitude of the plasma potential oscillation, can be estimated, similar to the method using pulse voltage.