| abstract |
A synthetic quartz glass substrate is prepared by (1) polishing a synthetic quartz glass substrate with a polishing slurry comprising colloidal particles, an ionic organic compound having an electric charge of the same type as the colloidal particles, and water, and (2) immersing the polished substrate in an acidic or basic solution for etching the substrate surface to a depth of 0.001-1 nm. The method produces a synthetic quartz glass substrate while preventing formation of defects of a size that is detectable by the high-sensitivity defect inspection tool, and providing the substrate with a satisfactory surface roughness. |