SUBSTRATE FOR BLANK MASK, BLANK MASK AND MANUFACTURING METHOD THEREOF

摘要

PURPOSE: A blank mask substrate, a blank mask, and a method for manufacturing the same are provided to manufacture a transparent substrate for the blank mask and allow the planarity of the transparent substrate to be equal to or less than 1.0um and the surface roughness of the transparent substrate to be equal to or less than 0.5nmRa. CONSTITUTION: A transparent substrate is composed of synthetic quartz glass. The thickness of the transparent substrate is more than or equal to 6.3mm, and the size of the transparent substrate is 152x152±0.2mm. A polishing process is performed to the effective area(10) of the synthetic quartz glass. Slurry, in which pH is regulated to be more than or equal to 4.0 and less than or equal to 12.0, is applied to the polishing process. The slurry contains a functional additive including etching effect or protective effect.