Patent attributes
An SiC wafer is produced from an SiC ingot by a method that includes a first modified layer forming step and a second modified layer forming step. In the first step, a first laser beam having a first power forms a plurality of discrete first modified layers at a first depth inside the ingot. In the second step, a second laser beam having a second power greater than the first power is applied to the ingot with the second laser beam focused at a depth greater than the first depth. A beam spot of the second laser beam overlaps any one of the plural first modified layers, thereby continuously forming a plurality of second modified layers connected in a line at the first depth. Cracks are formed on both sides of the line of the plural second modified layers so as to extend along a c-plane in the ingot.
