Pulsed plasma measurement method using harmonic analysis

Abstract

A phase delay harmonic analysis method (PDHAM) with high-time resolution is proposed to measure the plasma parameters of the pulsed plasmas. The PDHAM, which is based on the floating harmonic method, applies the phase delayed voltages to a probe tip, and obtains each of the currents in the phase-domain at a given time. The time resolution of this method is 0.8 mu s, and the total measurement is done within 2 s in the case of a pulsed plasma with a frequency of 1 kHz. The measurement result of the plasma parameters was compared with a conventional Langmuir probe using a boxcar mode, and shows good agreements. Because this PDHAM can measure the plasma parameters even in the processing discharges, it is expected to be usefully applied to plasma diagnostics for pulsed processing plasmas.