Abstract: A wafer processing method includes bonding one surface of a first wafer to a second wafer, the first wafer having a device region on the one surface, a peripheral surplus region, and a chamfered peripheral edge; forming an annular modified layer along a boundary of the device region and the peripheral surplus region by applying a laser beam to the first wafer from the other surface of the first wafer with a focal point of the laser beam placed at the boundary; after forming the modified layer, grinding the first wafer from the other surface to thin the first wafer to a finished thickness; and exerting an external force on the peripheral surplus region that is close to the peripheral edge with respect to a region in which the modified layer is formed, to thereby facilitate the separation of the peripheral surplus region.

Abstract: A method of processing a SiC ingot includes a resistance value measuring step of measuring an electric resistance value of an end face of the SiC ingot, a laser beam output adjusting step of adjusting the output of a laser beam according to the electric resistance value measured in the resistance value measuring step, and a peeling belt forming step in which, while a laser beam of such a wavelength as to be transmitted through the SiC ingot is being applied to the SiC ingot with a focal point of the laser beam positioned at a depth corresponding to the thickness of a wafer to be formed, the SiC ingot and the focal point are put into relative processing feeding in an X-axis direction to form a belt-shaped peeling belt in the inside of the SiC ingot.

Abstract: A method of processing a wafer includes forming a bonded wafer assembly by bonding one of opposite surfaces of a first wafer to a second wafer, the first wafer having a device region and an outer circumferential excessive region, applying a laser beam to the first wafer while positioning a focused spot of the laser beam radially inwardly from the outer circumferential edge of the first wafer, on an inclined plane that is progressively closer to the one of the opposite surfaces of the first wafer toward the outer circumferential edge, thereby forming a separation layer shaped as a side surface of a truncated cone, grinding the first wafer from the other one of the opposite surfaces thereof to thin down the first wafer to a predetermined thickness, and detecting whether or not the outer circumferential excessive region has been removed from the first wafer.

Abstract: A method for processing a bonded wafer includes forming a plurality of modified layers in a form of rings through positioning focal points of laser beams with a wavelength having transmissibility with respect to a first wafer inside the first wafer, from which a chamfered part and a notch are to be removed, from a back surface of the first wafer and executing irradiation, holding a second wafer side on a chuck table, and grinding the back surface of the first wafer to thin the first wafer. In forming the modified layer, the focal points of the laser beams are set in such a manner as to gradually get closer to a joining layer from an inner side toward an outer side of the first wafer in a radial direction to thereby form the modified layers as to widen toward the lower side.

Abstract: A processing method of a bonded wafer includes forming a plurality of modified layers in a form of rings through positioning focal points of laser beams with a wavelength having transmissibility with respect to a first wafer inside the first wafer, from which a chamfered part is to be removed, from a back surface of the first wafer and executing irradiation, holding a second wafer side on a chuck table, and grinding the back surface of the first wafer to thin the first wafer. In the forming the modified layers, the focal points of the laser beams are set in such a manner as to gradually get closer to a joining layer in a direction from an inner side of the first wafer toward an outer side thereof, so that the plurality of ring-shaped modified layers are formed in a form of descending stairs.

Abstract: A gas cooler includes a drain recovery part, a drain discharge flow path, a drain tank, and a ventilation flow path. In the drain recovery part, drain separated from gas is accumulated by cooling the gas in a cooling part. The drain tank includes a separation part in which the drain and the gas are separated, and a storage part in which the separated drain is stored. The drain discharge flow path has one end communicating with the drain recovery part and the other end communicating with the separation part. The ventilation flow path has one end communicating with the separation part, and the other end communicating with a gas flow path that leads to a downstream space above the drain recovery part and to a gas lead-out port.

Abstract: A wafer having a first surface, an opposite second surface, and an outer circumferential surface that includes a curved part curved outward in a protruding manner is separated into two wafers. Part of the wafer is removed along the curved part, and a separation origin is formed inside the wafer by positioning the focal point of a laser beam with a wavelength having transmissibility with respect to the wafer inside the wafer and executing irradiation with the laser beam while the focal point and the wafer are relatively moved in such a manner that the focal point is kept inside the wafer. The wafer is separated into two wafers by an external force.

Abstract: A method of manufacturing a chip formation wafer includes: forming an epitaxial film on a first main surface of a silicon carbide wafer to provide a processed wafer having one side adjacent to the epitaxial film and the other side; irradiating a laser beam into the processed wafer from the other side of the processed wafer so as to form an altered layer along a surface direction of the processed wafer; and separating the processed wafer with the altered layer as a boundary into a chip formation wafer having the one side of the processed wafer and a recycle wafer having the other side of the processed wafer. The processed wafer has a beveling portion at an outer edge portion of the processed wafer, and an area of the other side is larger than an area of the one side in the beveling portion.

Abstract: A water production system includes a filter unit that filters water to produce clear water, an ultraviolet light irradiator that irradiates, with ultraviolet light, the clear water produced by the filter unit, thereby degrading organic matter in the clear water, an ion exchange resin unit that purifies the clear water, in which the organic matter has been degraded by the ultraviolet light irradiator, into pure water, and a deaerated water production unit that deaerates the pure water to produce deaerated water.

Abstract: A wafer manufacturing method includes a peeling start point forming step of applying, to an ingot, a laser beam of such a wavelength as to be transmitted through the ingot, with a focal point of the laser beam positioned at a depth corresponding to the thickness of a wafer to be manufactured, from an end face of the ingot, to form a peeling start point, and a peeling step of peeling off, from the peeling start point, the wafer to be manufactured from the ingot. In the peeling step, degassed water is supplied to the end face of the ingot to generate a degassed water layer, and an ultrasonic wave is applied to break the peeling start point.

Abstract: A processing method for processing an SiC ingot includes a peel-off zone forming step of applying a processing pulsed laser beam having a wavelength transmittable through the ingot to the ingot while positioning a focused spot of the processing pulsed laser beam at a depth corresponding to a thickness of a wafer to be peeled off from the ingot, to form belt-shaped peel-off zones each including cracks in the ingot, a reflected beam detecting step of applying an inspecting laser beam having a wavelength transmittable through the ingot and reflectable from cracks of the peel-off zones and detecting an intensity of a beam reflected by the cracks, and a processing laser beam output power adjusting step of adjusting an output power of the processing pulsed laser beam to keep the intensity of the reflected beam detected in the reflected beam detecting step within a predetermined range.

Abstract: A wafer producing apparatus detects a facet area from an upper surface of an SiC ingot, sets X and Y coordinates of plural points lying on a boundary between the facet area and a nonfacet area in an XY plane, and sets a focal point of a laser beam having a transmission wavelength to SiC inside the SiC ingot at a predetermined depth from the upper surface of the SiC ingot. The predetermined depth corresponds to the thickness of the SiC wafer to be produced. A control unit increases the energy of the laser beam and raises a position of the focal point in applying the laser beam to the facet area as compared with the energy of the laser beam and a position of the focal point in applying the laser beam to the nonfacet area, according to the X and Y coordinates.

Abstract: A monocrystalline silicon wafer fabricated such that a particular crystal plane, e.g., a crystal plane (100), included in crystal planes {100} is exposed on each of face and reverse sides of the monocrystalline silicon wafer is irradiated with a laser beam along a first direction parallel to the particular crystal plane and inclined to a particular crystal orientation, e.g., a crystal orientation [010], included in crystal orientations <100> at an angle of 5° or less, thereby forming a peel-off layer that functions as separation initiating points between a part of the monocrystalline silicon wafer that belongs to the face side thereof and a part of the monocrystalline silicon wafer that belongs to the reverse side thereof.

Abstract: After separation layers are formed inside a single-crystal silicon ingot, a single-crystal silicon substrate is split off from the single-crystal silicon ingot with use of these separation layers as the point of origin. This can improve the productivity of the single-crystal silicon substrate compared with the case of manufacturing the single-crystal silicon substrate from the single-crystal silicon ingot by a wire saw.

Abstract: A wafer producing method includes a peel-off layer forming step of forming a peel-off layer by positioning a focused spot of a laser beam having a wavelength transmittable through an ingot to a depth corresponding to a thickness of the wafer to be produced from the ingot from a first end surface of the ingot and applying the laser beam to the ingot, a first chamfered portion forming step of forming a first chamfered portion by applying, from the first end surface side to a peripheral surplus region of the wafer, a laser beam having a wavelength absorbable by the wafer, a peeling-off step of peeling off the wafer to be produced, and a second chamfered portion forming step of forming a second chamfered portion by applying, from a peel-off surface side of the wafer, the laser beam having a wavelength absorbable by the wafer.

Abstract: A first peel-off layer extending along a side surface of a truncated cone that has a first bottom surface positioned near a face side of a wafer and a second bottom surface positioned within the wafer and smaller in diameter than the first bottom surface, and a second peel-off layer extending along the second bottom surface of the truncated cone are formed in the wafer. Then, external forces are exerted on the wafer thicknesswise of the wafer, thereby dividing the wafer along the first peel-off layer and the second peel-off layer that function as division initiating points.

Abstract: An SiC ingot forming method includes: a holding step of holding by a chuck table a cut section of a primitive SiC ingot cut from an SiC ingot growth base; a planarization step of grinding an end surface of the primitive SiC ingot held by the chuck table, to planarize the end surface; a c-plane detection step of detecting a c-plane of the primitive SiC ingot from the planarized end surface; a first end surface forming step of grinding the planarized end surface, to form a first end surface inclined at an off angle relative to the c-plane; and a second end surface forming step of holding the first end surface by the chuck table and grinding the cut section of the primitive SiC ingot in parallel to the first end surface, to form a second end surface.

Abstract: An ingot is processed by applying exciting light, and detecting fluorescence occurring from an upper surface of the ingot. A distribution of the number of photons of the fluorescence on the upper surface of the ingot is stored as two-dimensional data in association with XY coordinate positions, and a Z-coordinate position at which the two-dimensional data is obtained is also stored. A laser beam forms a peeling layer by irradiating the ingot while positioning the condensing point of the laser beam at a depth corresponding to the thickness of a wafer from the upper surface of the ingot. A wafer is separated from the ingot with the peeling layer as a starting point, and three-dimensional data is generated representing the distribution of the number of photons of the fluorescence in the whole of the ingot on the basis of two-dimensional data at each Z-coordinate position of the ingot.

Abstract: A method of producing a wafer from a hexagonal single-crystal ingot includes the steps of planarizing an end face of the hexagonal single-crystal ingot, forming a peel-off layer in the hexagonal single-crystal ingot by applying a pulsed laser beam whose wavelength is transmittable through the hexagonal single-crystal ingot while positioning a focal point of the pulsed laser beam in the hexagonal single-crystal ingot at a depth corresponding to a thickness of a wafer to be produced from the planarized end face of the hexagonal single-crystal ingot, recording a fabrication history on the planarized end face of the hexagonal single-crystal ingot by applying a pulsed laser beam to the hexagonal single-crystal ingot while positioning a focal point of the last-mentioned pulsed laser beam in a device-free area of the wafer to be produced.

Abstract: Irradiation conditions for a laser beam to respective ones of a plurality of regions included in the upper surface of an ingot are set according to the numbers of photons of fluorescence occurring when excitation light is irradiated to the respective regions. Here, it is to be understood that the number of the photons of the fluorescence occurring from a region of an ingot depends on the concentration of an impurity doped in the ingot. A separation layer can therefore be formed at a uniform depth from the upper surface of the ingot even if regions of different impurity concentrations are included in the ingot.