Characterization of RF He-N2/Ar mixture plasma via Langmuir probe and optical emission spectroscopy techniques

A Magnetic Pole Enhanced inductively coupled RF He-  N2/  Ar plasma is characterized using a Langmuir probe and optical emission spectroscopy (OES) techniques. The effect of helium mixing on electron density  (ne) and temperature  (Te), electron energy probability functions (EEPFs), [ N] atomic density, and N2  dissociation is investigated. A Langmuir probe and a zero slope method based on trace rare gas-optical emission spectroscopy (TRG-OES) are employed to measure the electron temperature. It is noted that the electron temperature shows an increasing trend for both methods. However, the temperature measured by a zero slope method Te(Z·S) approaches the temperature measured by a Langmuir probe; Te(L·P) at 56% and above helium concentration in the discharge. “Advance actinometry” is employed to monitor the variation in [ N] atomic density with helium concentration and gas pressure. It is noted that [ N] atomic density increases at 56% and above helium in the discharge, which is consistent with the trend ...