METHOD FOR INSPECTING SYNTHETIC QUARTZ GLASS

摘要

PURPOSE:To easily decide whether synthetic quartz glass is defective or non- defective by projecting excimer laser light to the quartz glass and checking if the quartz glass generates red fluorescence or not. CONSTITUTION:The excimer laser light (A) is projected to the synthetic quartz glass to be used as a substrate for a photomask and whether said glass generates the red fluorescence of about 650nm or not is visually decided. Since the glass which generates the fluorescence has the degraded transmission performance in a UV region and, therefore, the use of such glass is averted. The laser light of 193nm wavelength by ArF or 248nm wavelength by KrF is preferably used for the laser light A.