Wafer thermal separation method

The invention belongs to the field of semiconductor processing, and relates to a method for separating a thin wafer from a SiC crystal ingot, in particular to a wafer thermal separation method, which is characterized in that the thin wafer is separated on the crystal ingot on which a damage layer is formed by utilizing a thermal shrinkage material. According to the method, a thermal shrinkage material is bonded to the upper surface of a to-be-separated wafer on a crystal ingot through an adhesive, after the adhesive is completely cured, the thermal shrinkage material is heated to be shrunk, under the action of shrinkage force, a damage layer of the crystal ingot generates cracks under the action of tensile stress, and the to-be-separated wafer is gradually separated from the crystal ingot from the edge to the interior. Particularly, a selective heating mode is adopted in the heating process, so that the shrinkage degree of the heat-shrinkable material is controllably carried out, and wafer breakage caused by