Patent attributes
A wafer producing method produces a hexagonal single crystal wafer from a hexagonal single crystal ingot. The method includes a separation start point forming step of setting the focal point of a laser beam to the inside of the ingot at a predetermined depth from the upper surface of the ingot, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot while relatively moving the focal point and the ingot to thereby form a modified layer parallel to the upper surface of the ingot and cracks extending from the modified layer, thus forming a separation start point. The separation start point forming step includes an indexing step of relatively moving the focal point in a direction of formation of an off angle to thereby index the focal point by a predetermined index amount.
