On The Influence Of Metastable States And The Behavior Of The EEDF In The Characterization Of The Negative Glow Of A N2-Ar Discharge By OES

ISOLA, L M; LOPEZ, M; GOMEZ, B J; GUERRA, V

Santiago

Congreso; 15th International Congress on Plasma Physics (ICPP 2010); 2010

Optical emission spectroscopy (OES) is an essential diagnostic technique in many plasma systems, such as those used for surface treatments or fabrication of thin films. Despite the simplicity of application of OES its interpretation is not straightforward. In particular, it requires the use of models, which, due to the complexity and variety of discharge conditions, have not yet been fully understood [1]–[3]. In addition, Langmuir probes have been widely used to characterize plasmas. They allow the measurement of several parameters of interest, such as the electron density and temperature, as well as the determination of the electron energy distribution function (EEDF) by numerical derivation of the characteristic V − I [4] or by probe-current modulation [5]. In this work, the negative glow of an Ar-N2 plasma at a pressure of 2.5 Torr was investigated both by OES and Langmuir probes, for different mixture concentrations. The main purpose of this study was to verify how metastable states and the behavior of the EEDF may influence the interpretation of OES data