Patent ID: 11469094

Abstract:
A method of producing a wafer from a hexagonal single-crystal ingot includes the steps of planarizing an end face of the hexagonal single-crystal ingot, forming a peel-off layer in the hexagonal single-crystal ingot by applying a pulsed laser beam whose wavelength is transmittable through the hexagonal single-crystal ingot while positioning a focal point of the pulsed laser beam in the hexagonal single-crystal ingot at a depth corresponding to a thickness of a wafer to be produced from the planarized end face of the hexagonal single-crystal ingot, recording a fabrication history on the planarized end face of the hexagonal single-crystal ingot by applying a pulsed laser beam to the hexagonal single-crystal ingot while positioning a focal point of the last-mentioned pulsed laser beam in a device-free area of the wafer to be produced.