| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a sapphire substrate having a principal surface ordinarily set as a concave surface and a reduced warp amount by a simple process without optimizing a heat treatment condition for every substrate.SOLUTION: The method for manufacturing a sapphire substrate comprises: a plurality of steps of processing a substrate 10 obtained by slicing a sapphire ingot; the single side lapping step of performing single side lapping processing on at least a rear surface 10B of the substrate 10 until the principal surface 10A of the substrate 10 reaches a concave surface; and the heat treatment step of relaxing working stress generated in the substrate 10 after the single side lapping step. Thereby, the sapphire substrate having a diameter of at least 4 inch and a warp amount of 30 μm or less on the rear surface side after the heat treatment step is obtained. |
