| 摘要 |
PROBLEM TO BE SOLVED: To provide a sapphire substrate produced by shortening or eliminating production processes in a substrate having a large diameter equal to or more than 4 inches and whose warp quantity, waviness quantity, and quantity of thickness irregularity are reduced.SOLUTION: The production processes of a sapphire substrate include at least a both side wet blast process and a polishing process. The both side wet blast process performs wet blast processing on the whole surface of a substrate 10 from a center of the substrate 10 toward a peripheral edge direction of the substrate 10 on a convex surface of the substrate 10. And the wet blast processing is performed on the whole surface of the substrate 10 from the peripheral edge direction of the substrate 10 toward the center of the substrate 10 on a concave part of the substrate 10. |
