Patent attributes
A SiC wafer is produced from an SiC ingot having an end surface by setting the focal point of a laser beam at a predetermined depth from the end surface. The depth corresponds to the thickness of the SiC wafer to be produced. The laser beam is applied to the end surface of the SiC ingot while relatively moving the focal point and the SiC ingot to thereby form a modified layer parallel to the end surface and cracks extending from the modified layer, thus forming a separation start point. The separation start point is formed by setting the numerical aperture of a focusing lens to form the focal point to 0.45 to 0.9 and substantially setting the M2 factor of the laser beam between 5 and 50 to thereby set the diameter of the focal point to 15 to 150 μm.
