| 摘要 |
The purpose of the present invention is to provide a wafer producing method capable of efficiently producing a wafer from an ingot. The wafer producing method for producing a wafer from a hexagonal single crystal ingot comprises: a separation start point forming step of setting the focal point of a laser beam of a wavelength with transmittance with respect to the hexagonal single crystal ingot at a depth corresponding to the thickness of the wafer to be produced from the surface, radiating the laser beam to the surface by relatively moving the focal point and the hexagonal single crystal ingot, and forming a modified layer in parallel to the surface and cracks extending from the modified layer, thereby forming a separation start point; and a wafer separating step of separating a plate-shaped member having a thickness corresponding to the thickness of the wafer from the hexagonal single crystal ingot from the separation start point after conducting the separation start point forming step, thereby producing a hexagonal single crystal wafer. The separation start point forming step includes: a modified layer forming step of relatively moving the focal point of the laser beam in a direction perpendicular to a direction in which the c-axis is inclined by an off angle with respect to a normal to the surface and the off angle is formed between the surface and the c-plane, thereby forming a linear modified layer; and an indexing step of relatively moving the focal point in the direction in which the off angle is formed, thereby indexing the focal point by a predetermined amount. |
