SYNTHETIC QUARTZ GLASS SUBSTRATE AND MAKING METHOD

摘要

PURPOSE: A synthetic quartz glass substrate and a manufacturing method thereof are provided to control the flatness of the surface of the substrate using useful regions and shapes. CONSTITUTION: A synthetic quartz glass substrate(1) has a square shape with one side forming an inclined form from the center square(A) of the surface toward the surface outer circumference. The length of one side on the inclined form is 6 inches. The flatness of the center square is less than 50nm. The flatness of a frame portion(2) on the glass substrate around the center square is less than 150nm. TiO2 is doped on the synthetic quartz glass substrate.