Dielectric window contamination prevention device, self plasma light emission spectrum device, and particle measurement device

摘要

PURPOSE: A dielectric window pollution preventing apparatus, a self plasma light emission spectrum device, and a particle measuring device are provided to prevent a dielectric window from being polluted due to process gas and process byproducts by spraying pollution preventing gas to the dielectric window through a nozzle unit. CONSTITUTION: A dielectric window is combined with a flange attached to a vacuum container. A nozzle unit(520a,520b) is arranged around the dielectric window or flange. The nozzle unit provides the pollution preventing gas to the dielectric window. The flange includes a first flange(515a) and a second flange(515b). The dielectric window includes a first dielectric window(528a) combined with the first flange and a second dielectric window(528b) combined with the second flange.