Eur. Phys. J. D 47, 395-402 (2008)
https://doi.org/10.1140/epjd/e2008-00055-9

Langmuir probe and spectroscopic studies of RF generated helium-nitrogen mixture plasma

Department of Physics, Quaid-i-Azam University, 45320 Islamabad, Pakistan

Corresponding author: ^a mzakaullah@qau.edu.pk

Received: 11 October 2007
Revised: 31 January 2008
Published online: 21 March 2008

Abstract

This paper reports the effect of helium percentage variation in a capacitive RF helium-nitrogen mixture plasma on various plasma parameters and concentration of nitrogen active species (N₂(C³Π _u) and N₂⁺(B²Σ _u⁺)). Langmuir probe is used for determination of electron energy distribution functions, effective electron temperature, plasma potential and electron density. Optical emission spectroscopy is used for determination of electron temperature from Boltzmann's plot of He–I lines and the relative changes in the concentration of active species by measuring the emission intensities of nitrogen (0-0) bands of the second positive and the first negative systems. The results demonstrate that electron temperature, electron density and concentration of active species increase significantly with increase in helium percentage in the mixture and RF power.