A new method of electron temperature determination in unmagnetized and magnetized RF plasmas without RF compensating circuit

Abstract

Collected current versus applied voltage(I-V) curve of Langmuir probe in RF plasma is severely distorted by RF fluctuations to cause overestimation of electron temperature. RF compensation circuit has been used to obtain the un-distorted I-V curve, yet it produces time-averaged one. A new and simple method is proposed to get time-resolved I-V curve by picking the synchronized RF signals with digital oscilloscope and Labview program This technique is tested in magnetized Helicon plasmas and unmagnetized capacitive coupled RF plasmas.