Color Change Characteristics of Plasma Indicators by Vacuum Ultraviolet Irradiation

In this study, we investigated whether "Plasma Indicator
^TM
(hereinafter called "Indicator") for atmospheric plasma and desmear," which detect oxygen-based radicals in plasma, could be used to characterize vacuum ultraviolet (VUV) irradiation from an excimer lamp. We clarified that both Indicators changed color according to the VUV irradiation dose and would be useful for relative evaluation such as confirming the reproducibility of VUV irradiation. We also proposed that an appropriate Indicator suitable for atmospheric plasma or for desmear must be chosen for each application based on the required VUV irradiation dose.