Abstract: A wafer manufacturing method for obtaining a wafer from an ingot includes the following procedure, steps or processes. A surface of one end side of the ingot in a height direction thereof is irradiated with a laser beam to which the ingot has transparency, thereby forming a peeling layer at a depth position corresponding to a thickness of the wafer from the surface. At this moment, the laser beam is irradiated such that a frequency of irradiation in a facet region is higher than that in a non-facet region. A wafer precursor as a portion between the surface of the ingot and the peeling layer is peeled from the ingot at the peeling layer. A major surface of a peeling body having a plate like shape, the peeling body being obtained by the wafer peeling step, is planarized electrically, chemically and mechanically, thereby obtaining a wafer.

Abstract: A surface of one end side of an ingot in a height direction thereof is irradiated with a laser beam having a permeability to the ingot, thereby forming a peeling layer at a depth position corresponding to a thickness of the wafer from the surface. A laser scanning irradiating the laser beam is performed for a plurality of times changing the irradiation position in a second direction while causing an irradiation position of the laser beam to move in a first direction. With a single laser scanning, a plurality of laser beams are irradiated in which irradiation positions are different in the first direction and the second direction.

Abstract: A wafer production method for producing a wafer from an ingot oriented to have a c-axis inclined in an off-angle direction at an off-angle more than zero degree From a central axis includes steps of emitting a laser beam to a top surface that is one of end surfaces of the ingot opposed to each other in height direction thereof to form a separation layer at a depth from the top surface of the ingot which corresponds to a thickness of the wafer, applying a physical load in a single direction to a first end that is one of ends of the ingot which are opposed to each other in an off-angle direction to remove a wafer precursor from the ingot at the separation layer, and planarizing a major surface of a removed object derived by separating the wafer precursor from the ingot at the separation layer, thereby forming a wafer. The ingot has a given degree of transmittance to the laser beam. The wafer precursor is created by a portion of the ingot between the top surface of the ingot and the separation layer.

Abstract: A manufacturing method for wafers includes: radiating a laser beam to a planned cutoff surface where the ingot is to be cutoff; and forming, with the radiation of the laser beam, a plurality of reformed sections at the planned cutoff surface to extend a crack from the reformed section, thereby slicing wafers, wherein an energy density of the laser beam exceeds a reforming threshold. The energy density satisfies at least one of conditions of a peak value of the energy density is lower than or equal to 44 J/cm2, a rising rate of the energy density at a portion corresponding to the most shallow position where the energy density reaches the reforming threshold Eth is larger than or equal to 1000 J/cm3, and a range of depth where the energy density exceeds the reforming threshold is smaller than or equal to 30 ?m.