Fundamentals of planar-type inductively coupled thermal plasmas on a substrate for large-area material processing

In this work, the fundamentals of planar-type Ar inductively coupled thermal plasmas (ICTPs) with oxygen molecular gas on a substrate have been studied. Previously, aiming at large-area material processing, we developed a planar-type ICTP torch with a rectangular quartz vessel instead of a conventional cylindrical tube. For the adoption of such planar-type ICTP to material processing, it is necessary to sustain the ICTP with molecular gases on a substrate stably and uniformly. To determine the uniformity of the ICTP formed on the substrate, spectroscopic observation was carried out at 3mm above the substrate. Results showed that the radiation intensities of specified O atomic lines were almost uniformly detected along the surface of the substrate. This means that excited O atoms, which are important radicals for thermal plasma oxidation, are present in the planar-type ICTP uniformly on the substrate. (C) 2016 The Japan Society of Applied Physics