Probe system with bias compensation using a laser heated emissive probe for RF discharge plasma diagnostics

A new probe system consisting of a bias compensation circuit and a CO2-laser-heated emissive probe is presented. This system has been verified to have a sufficiently high time response to eliminate the voltage variation between plasma and probe caused by the applied RF voltages. The time-resolved single probe measurement of a 13.56 MHz RF discharge plasma has been successfully carried out using this system and the results show that both the electron temperature and the electron density vary in the same period of applied RF voltage and that the electron energy distribution function of the plasma is almost Maxwellian except in the high energy tail region.