Spatial distribution diagnosis of electron temperature and density of argon inductively coupled plasma by tomographic optical emission spectroscopic measurement and collisional-radiative model

Abstract

There are few reported cases in which the spatial distribution of spectral emission coefficients of plasmas from tomographic optical emission spectroscopy measurements is analyzed based on a collisional-radiative model to diagnose the spatial distribution electron temperature of Te and density Ne. This study aimed at in situ diagnosis of process plasma. The spectral radiance of 18 lines-of-sight was measured simultaneously in argon inductively coupled plasma. The spatial distribution of the excited level number density distribution was calculated from the spatial distribution of spectral emission coefficients obtained from spectral tomography calculations. The three-dimensional distribution of Te and Ne was analyzed using a collisional-radiative model from the obtained spatial distribution of the excited levels number density. The effects of power and pressure on the dependence of the spatial distribution of Te and Ne were discussed. Furthermore, data processing methods for spectral tomographic measurements with coarse wavelength resolution were also discussed.