SAPPHIRE SUBSTRATE AND MANUFACTURING METHOD OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a sapphire substrate which inhibits cracks from being caused by temperature gradient in the sapphire substrate.SOLUTION: A sapphire substrate includes: a main surface; a rear surface facing the main surface; and an end surface. Chamfered parts are provided between the main surface and the end surface and between the rear surface and the end surface. Mirror polishing is performed to the end surface and the chamfered parts.