Abstract: A ? gallium oxide substrate manufacturing method for manufacturing a substrate from a workpiece formed of ? gallium oxide includes a separation layer forming step of applying a laser beam of such a wavelength as to be transmitted through the ? gallium oxide to the workpiece, with a focal point of the laser beam positioned at a predetermined depth from a front surface of the workpiece, to thereby form a separation layer including a modified part and a crack extending from the modified part, inside the workpiece, and a separation step of exerting an external force on the workpiece to thereby separate the substrate from the workpiece with the separation layer as a start point, after the separation layer forming step.

Abstract: A wafer production method for producing, from a workpiece being a nitride or oxide semiconductor, a wafer thinner than the workpiece, includes holding a back surface of the workpiece; forming a separation layer in an outer peripheral region of the held workpiece as defined herein; forming a separation layer in an inner region inside the outer peripheral region of the workpiece as defined herein, after the forming of the separation layer in the outer peripheral region; and separating a plate-shaped object from the workpiece as the wafer with the separation layers formed in the outer peripheral region and the inner region as a start point, and the forming of the separation layer in the outer peripheral region includes forming the separation layer at an inner position, and forming the separation layer at an outer position after the forming of the separation layer at the inner position.

Abstract: A grinding apparatus capable of easily processing an end surface of a diamond substrate into a planar surface, where the grinding apparatus includes a holding unit for holding the diamond substrate, a grinding unit including a grinding tool for grinding the end surface of the diamond substrate held by the holding unit, and a grinding feed unit for grinding-feeding the grinding unit in a direction that brings the grinding unit closer to and away from the end surface of the diamond substrate held by the holding unit. The grinding tool has a base and a grinding blade mounted on the base. The grinding blade is made of iron and acts on the end surface of the diamond substrate to cause a reaction between the iron and carbon of diamond and generate a compound containing austenite, thereby grinding the end surface of the diamond substrate.

Abstract: A substrate manufacturing method includes applying a laser beam of a wavelength transmittable through a material of a workpiece, thereby forming a peel-off layer inside the workpiece, and after the forming of the peel-off layer, with the peel-off layer as a starting point of separation, separating the workpiece, thereby manufacturing a substrate. In the forming of the peel-off layer, by alternately repeating moving the workpiece and a focusing point at which the laser beam is focused relative to each other along a first direction, in a state in which the focusing point is positioned inside the workpiece, and moving the workpiece and a position at which the focusing point is formed relative to each other along a second direction perpendicular to the first direction, the peel-off layer including first modified portions and second modified portions which are alternately lined up in the second direction is formed.

Abstract: A substrate manufacturing method includes peel-off layer forming of forming a plurality of rows of peel-off layers inside a workpiece, and, after the peel-off layer forming, separating the workpiece with the plurality of rows of peel-off layers being used as separation initiating points, to manufacture substrates. The peel-off layer forming includes first processing of forming a plurality of rows of first peel-off layers each including a modified portion and each being spaced from one another, and second processing of, after the first processing, forming a plurality of rows of second peel-off layers each including a modified portion and a crack extending from the modified portion and each being located between a pair of adjacent first peel-off layers of the plurality of rows of first peel-off layers.

Abstract: A method of manufacturing a substrate from a workpiece includes a separation layer forming step of moving the workpiece and a focused spot of a laser beam having a wavelength transmittable through the gallium oxide and a repetitively pulsed power output relatively to each other perpendicularly to thicknesswise directions of the workpiece while positioning the focused spot within the workpiece, thereby forming in the workpiece a separation layer including a plurality of modified regions arrayed in a direction along which the focused spot travels in the workpiece and cracks developed from each of the modified regions, and after the separation layer forming step, a cleaving step of cleaving the workpiece along the separation layer, thereby manufacturing the substrate from the workpiece.

Abstract: A laser processing method for forming a separation layer inside an ingot by using a laser beam includes a manufacturing a substrate by separating a portion of the ingot, the portion being located on a side of one side of the ingot, then evaluating the substrate to acquire information on optical characteristics in each of a plurality of regions on the one side of the ingot, then setting, for every one of the plurality of regions, irradiation conditions for the laser beam with reference to the information, and then forming the separation layer inside the ingot by irradiating the ingot with the laser beam from the one side with a focal point at which the laser beam is focused inside of the ingot.

Abstract: A ? gallium oxide substrate manufacturing method for manufacturing a substrate from a workpiece formed of ? gallium oxide includes a separation layer forming step of applying a laser beam of such a wavelength as to be transmitted through the ? gallium oxide to the workpiece, with a focal point of the laser beam positioned at a predetermined depth from a front surface of the workpiece, to thereby form a separation layer including a modified part and a crack extending from the modified part, inside the workpiece, and a separation step of exerting an external force on the workpiece to thereby separate the substrate from the workpiece with the separation layer as a start point, after the separation layer forming step.