Generation of integrated atmospheric-pressure microplasmas

This work is based on the motivation that by integrating microplasmas confined in a small volume, a large area high-density plasma source could be developed. Firstly, He gas microplasmas were generated by cpacitively coupled plasma (CCP) and inductively coupled type plasma (ICP-type) in single small diameter ceramic tubes supplied with 13.56 MHz power via electrodes. Then, based upon the obtained characteristics, sustaining voltage and RF power variations were discussed for integrating tubes two and three dimensionally. However, the presence of the CCP component was noticed from the weak discharge around the center of the highly integrated ICP-type. Therefore, the generation of planar-type plasma was also studied using narrow comb electrodes, which enabled us to produce the discharge at a lower voltage in accordance with Paschen's law. As a result, uniform plasma was successfully generated in an area of 12 mm x 12 mm. Atmospheric-pressure microplasma generation of pure N-2 gas as well as He gas was realized by planar type plasma at low sustaining voltages.