Spectroscopic Analysis of Argon and Zinc Emission Lines in Argon-Nitrogen Mixed Gas Inductively Coupled Plasma

Abstract

The characteristics of an argon-matrix inductively coupled plasma (ICP) containing small amounts of nitrogen gas are considerably different from those of a pure argon ICP. The role of nitrogen in the mixed gas ICP is investigated from spectroscopic analyses of argon emission lines. The spectral widths of the argon and hydrogen lines increase with the amount of nitrogen gas added, which means that the electron number density of the plasma is raised. The emission intensities of the argon and zinc lines also increase, and the variation in these intensities corresponds to that in the spectral width of the argon and hydrogen lines when nitrogen is added in the plasma. These observations suggest that the nitrogen addition causes a great change in the region of the ICP from which the argon lines are dominantly emitted. Furthermore, the intensity of the NO band heads decreases in the argon-nitrogen mixed gas ICPs, implying that the increment in the plasma temperature contributes to the decomposition of NO radicals.