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

Abstract

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 3 mm 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.

Recent development of new inductively coupled thermal plasmas for materials processing

“…Conventional cylindrical torches are only suitable to a slight degree for large-area material processing because thermal plasma in the cylindrical quartz tube shrinks as a result of the Lorentz force. For this reason, planartype ICTP torches have been developed for large-area materials processing [77]- [79].…”

“…Figure 18 shows the configuration of the planar-ICTP torch [77]. The planar-ICTP has a rectangular quartz vessel and an RF coil sandwiching this vessel.…”

“…The MITP+TCFF method is useful to synthesize nanoparticles at a high production rate. Finally, topics will be described for large-area materials processing by thermal plasma [77][78][79][80][81]. For this purpose, some improvements and developments have been made to ICTP torches.…”

Review of Thermal Plasma Simulation Technique

“…However, the conventional cylindrical ICTP is hardly adequate to large‐area material processing because it needs a large volume and thus a high input power to sustain the ICTP for large‐area processing. For the purpose of large‐area surface modification using thermal plasmas, one of the authors (YT) has developed a planar type of ICTP and then a loop type of ICTP (loop‐ICTP) . The loop‐ICTP is established inside the loop quartz tube, and also a part of the ICTP is formed linearly on the substrate.…”