Patent ID: 11958132
Assignee: DISCO CORPORATION
Field: Machine tools (Mechanical engineering)
Classification: CPC B | IPC B

Claim 2:
3. A laser processing apparatus that forms a peeling belt in a SiC ingot, the laser processing apparatus comprising:
a holding table that holds the SiC ingot;
a laser beam applying unit that, in a case wherein a c-plane is inclined relative to an end face of the SiC ingot held by the holding table, an off angle is present, between the end face of the SiC ingot and the c-plane, the off angle is parallel to an X-axis direction and the X-axis direction is orthogonal to a Y-axis direction, includes a light condenser for applying a laser beam of such a wavelength as to be transmitted through the SiC ingot to the SiC ingot with a focal point of the laser beam positioned at a depth corresponding to a thickness of a wafer to be formed and forms a belt-shaped peeling belt in which a crack extends along the c-plane from a part where SiC is separated into Si and C;
an X-axis feeding mechanism that puts the holding table and the light condenser into relative processing feeding in the X-axis direction;
a Y-axis feeding mechanism that puts the holding table and the light condenser into relative indexing feeding in the Y-axis direction;
a resistance value measuring instrument that measures an electric resistance value of the end face of the SiC ingot; and
a control unit that adjusts output of the laser beam according to the electric resistance value measured by the resistance value measuring instrument.