SiC ingot forming method

A silicon carbide (SiC) ingot forming method comprising:

• a holding step of holding by a chuck table a cut section of a primitive SiC ingot cut from an SiC ingot growth base;
• a planarization step of grinding an end surface of the primitive SiC ingot held by the chuck table, to planarize the end surface;
• a c-plane detection step of detecting a c-plane of the primitive SiC ingot from the planarized end surface;
• a first end surface forming step of grinding the planarized end surface, to form a first end surface inclined at an off angle relative to the c-plane;
• and
• a second end surface forming step of holding the first end surface by the chuck table and grinding the cut section of the primitive SiC ingot in parallel to the first end surface, to form a second end surface, and
• wherein in the c-plane detection step, a laser beam of such a wavelength as to be transmitted through SiC is applied to the primitive SiC ingot from the end surface planarized in the planarization step, with a focal point of the laser beam positioned inside the primitive SiC ingot, to form a modified layer in which SiC is separated into silicon (Si) and carbon (C) and a crack extends along the c-plane, and the modified layer is observed from the planarized end surface to detect the c-plane, and
• further wherein the observing of the modified layer also includes measuring a depth of the crack extending along the c-plane, with respect to the planarized end surface, at a plurality of locations to detect an inclination angle and inclination direction of the c-plane.