A method of manufacturing a diamond substrate includes: a step of placing a laser condensing unit 190 configured to condense laser light B so as to face an upper surface 10a of a block 10 of single crystal diamond, a step of forming a modified layer 20, which includes a processing mark 21 of graphite and a crack 22b extending along a surface (111) around the processing mark 21, in a partial region of the upper surface 10a of the block 10 along the surface (111) of the single crystal diamond, along the surface (111) of the single crystal diamond at a predetermined depth from the upper surface 10a of the block 10 by radiating the laser light B on the upper surface 10a of the block 10 from the laser condensing unit 190 under predetermined conditions and condensing the laser light B inside the block 10, and moving the laser condensing unit 190 and the block 10 in a relative manner two-dimensionally, and a step of forming a cleavage plane 25 at the predetermined depth of the remaining region of the upper surface 10a of the block 10 by spontaneously propagating cleavage from the modified layer 20.

A method of manufacturing a diamond substrate includes: a step of placing a laser condensing unit 190 configured to condense laser light B so as to face an upper surface 10a of a block 10 of single crystal diamond, a step of forming a modified layer 20, which includes a processing mark 21 of graphite and a crack 22b extending along a surface (111) around the processing mark 21, in a partial region of the upper surface 10a of the block 10 along the surface (111) of the single crystal diamond, along the surface (111) of the single crystal diamond at a predetermined depth from the upper surface 10a of the block 10 by radiating the laser light B on the upper surface 10a of the block 10 from the laser condensing unit 190 under predetermined conditions and condensing the laser light B inside the block 10, and moving the laser condensing unit 190 and the block 10 in a relative manner two-dimensionally, and a step of forming a cleavage plane 25 at the predetermined depth of the remaining region of the upper surface 10a of the block 10 by spontaneously propagating cleavage from the modified layer 20.

A method for manufacturing a cutting tool according to one embodiment is a method for manufacturing a cutting tool, the cutting tool including a base material and a diamond single crystal material fixed to the base material, the diamond single crystal material having a rake face, a flank face continuous with the rake face, and a cutting edge formed by a ridgeline serving as a boundary between the rake face and the flank face. The method for manufacturing a cutting tool according to one form of the present disclosure includes a flank face irradiation step of applying a laser to the diamond single crystal material along the cutting edge from a side of the flank face. The laser has a pulse width of 1×10.sup.−12 seconds or less and a peak output of less than 1 W in the flank face irradiation step.

A method for manufacturing a cutting tool according to one embodiment is a method for manufacturing a cutting tool, the cutting tool including a base material and a diamond single crystal material fixed to the base material, the diamond single crystal material having a rake face, a flank face continuous with the rake face, and a cutting edge formed by a ridgeline serving as a boundary between the rake face and the flank face. The method for manufacturing a cutting tool according to one form of the present disclosure includes a flank face irradiation step of applying a laser to the diamond single crystal material along the cutting edge from a side of the flank face. The laser has a pulse width of 1×10.sup.−12 seconds or less and a peak output of less than 1 W in the flank face irradiation step.

A method of producing a glass substrate having a hole is provided. The method includes preparing the glass substrate having a first surface and a second surface facing each other; forming a hole in the glass substrate with a laser; and annealing the glass substrate placed on a first support substrate having a thermal expansion coefficient whose difference from a thermal expansion coefficient of the glass substrate is less than or equal to 1 ppm/K, where the first support substrate is placed on a second support substrate having a thermal expansion coefficient of less than or equal to 10 ppm/K.

A wafer processing method includes a polyester sheet providing step of positioning a wafer in an inside opening of a ring frame and providing a polyester sheet on a back side or a front side of the wafer and on a back side of the ring frame, a uniting step of heating the polyester sheet as applying a pressure to the polyester sheet to thereby unite the wafer and the ring frame through the polyester sheet by thermocompression bonding, a dividing step of applying a laser beam to the wafer to form shield tunnels in the wafer, thereby dividing the wafer into individual device chips, and a pickup step of applying an ultrasonic wave to the polyester sheet, pushing up each device chip through the polyester sheet, and picking up each device chip from the polyester sheet.

A wafer processing method includes a polyester sheet providing step of positioning a wafer in an inside opening of a ring frame and providing a polyester sheet on a back side or a front side of the wafer and on a back side of the ring frame, a uniting step of heating the polyester sheet as applying a pressure to the polyester sheet to thereby unite the wafer and the ring frame through the polyester sheet by thermocompression bonding, a dividing step of applying a laser beam to the wafer to form shield tunnels in the wafer, thereby dividing the wafer into individual device chips, and a pickup step of applying an ultrasonic wave to the polyester sheet, pushing up each device chip through the polyester sheet, and picking up each device chip from the polyester sheet.

A laser processing method for cutting a base material, including stacked first and second layers having different thermal expansion coefficients, includes radiating laser light onto a first inter-layer part under prescribed first inter-layer conditions, to cut the first inter-layer part, which extends from a position in the vicinity of a layer boundary inward of the surface of the second layer, through the layer boundary between the second layer and the first layer, to a position in the vicinity of a layer boundary inward of said one surface of the first layer, and radiating the laser light onto a part of the first layer inward from the position in the vicinity of the layer boundary, under first conditions, to cut the first layer, wherein the first inter-layer condition is a condition under which the amount of heat input by the laser light is less than under the first condition.

A laser processing method for cutting a base material, including stacked first and second layers having different thermal expansion coefficients, includes radiating laser light onto a first inter-layer part under prescribed first inter-layer conditions, to cut the first inter-layer part, which extends from a position in the vicinity of a layer boundary inward of the surface of the second layer, through the layer boundary between the second layer and the first layer, to a position in the vicinity of a layer boundary inward of said one surface of the first layer, and radiating the laser light onto a part of the first layer inward from the position in the vicinity of the layer boundary, under first conditions, to cut the first layer, wherein the first inter-layer condition is a condition under which the amount of heat input by the laser light is less than under the first condition.

A system and method for forming a structure with steep walls (walls having an angle greater than 60° with respect to a level plane) through one or more incremental sheet forming operations is provided. The method includes a workpiece with an inner region and an outer region that are separated by a boundary region. The boundary region includes a plurality of openings and a plurality of connecting elements. The openings are cut into the workpiece using a boundary region cutting tool. A forming tool is configured to operate on the inner region after the boundary region cutting operation has been completed. At least one control unit is in communication with the forming tool. The at least one control unit operates the forming tool to form the structure from the inner region.