Spatial distribution of electron temperature and density in argon RF-biased ICP with non-quasi-neutrality effects

Two-dimensional horizontal distributions of electron temperature and density in argon inductively coupled plasma (ICP) with an applied radio frequency bias were obtained using optical emission spectroscopy (OES) combined with a spectral tomography algorithm. Additionally, Langmuir probe measurements were conducted along the diameter of the chamber to determine the spatial distributions of electron and ion densities. The results revealed a significant deviation from the assumption of quasi-neutrality near the chamber center at a height of 12 mm above the substrate. Based on this observation, the Ar collisional-radiative model results obtained from OES were recalculated under the conditions of 1 Pa discharge pressure, 600 W ICP power, and 100 W bias power, with modifications to account for the observed deviation from quasi-neutrality.