Abstract: A wafer formed from an SiC substrate having a first surface and a second surface is divided into individual device chips. A division start point formed by a laser has a depth corresponding to the finished thickness of each device chip along each division line formed on the first surface. The focal point of the laser beam is set inside the SiC substrate at a predetermined depth from the second surface, and the laser beam is applied to the second surface while relatively moving the focal point and the SiC substrate to thereby form a modified layer parallel to the first surface and cracks extending from the modified layer along a c-plane, thus forming a separation start point. An external force is applied to the wafer, thereby separating the wafer into a first wafer having the first surface and a second wafer having the second surface.

Abstract: Disclosed herein is a wafer thinning method for thinning a wafer formed from an SiC substrate having a first surface and a second surface opposite to the first surface. The wafer thinning method includes an annular groove forming step of forming an annular groove on the second surface of the SiC substrate in an annular area corresponding to the boundary between a device area and a peripheral marginal area in the condition where a thickness corresponding to the finished thickness of the wafer after thinning is left, and a separation start point forming step of applying the laser beam to the second surface as relatively moving a focal point and the SiC substrate to thereby form a modified layer and cracks inside the SiC substrate at the predetermined depth.

Abstract: Disclosed herein is a wafer thinning method for thinning a wafer formed from an SiC substrate having a first surface and a second surface opposite to the first surface. The wafer thinning method includes a separation start point forming step of applying the laser beam to the second surface as relatively moving the focal point and the SiC substrate to thereby form a modified layer parallel to the first surface and cracks inside the SiC substrate at the predetermined depth, thus forming a separation start point, and a wafer thinning step of applying an external force to the wafer, thereby separating the wafer into a first wafer having the first surface of the SiC substrate and a second wafer having the second surface of the SiC substrate at the separation start point.

Abstract: A hexagonal single crystal wafer is produced from a hexagonal single crystal ingot. The depth of the focal point of a laser beam is gradually changed from a shallow position not reaching the depth corresponding to the desired thickness of the wafer to a deep position corresponding to the desired thickness of the wafer in such a manner that a parabola is described by the path of the focal point. When the spot area of the laser beam on the upper surface of the ingot becomes a predetermined maximum value, the deep position of the focal point is maintained.

Abstract: There is provided a polycrystalline SiC wafer producing method. In this method, in a modified layer forming step for forming an interface for producing a polycrystalline SiC wafer from a polycrystalline SiC ingot, the formed interface is a surface formed by linking of modified layers formed in such a manner that an initial modified layer is formed through splitting of polycrystalline SiC into amorphous silicon and amorphous carbon at the light focus point of a pulse laser beam and then polycrystalline SiC splits into amorphous silicon and amorphous carbon at a position at which the power density is constant with absorption of the continuously-emitted pulse laser beam by amorphous carbon formed in advance.

Abstract: A pressure vessel, comprising: a vessel body having a rectangular parallelepiped shape for containing high pressure gas; a dividing wall in the form of a plate and disposed in the vessel body; and a plurality of ribs disposed on an outer surface of the vessel body. The vessel body includes: a top wall having a rectangular shape; a bottom wall having a rectangular shape and facing the top wall; and a surrounding wall joining a peripheral edge of the top wall and a peripheral edge of the bottom wall. The dividing wall is disposed in the vessel body to define a first chamber having a rectangular parallelepiped shape and a second chamber having a rectangular parallelepiped shape in cooperation with the vessel body. Each of the plurality of ribs extends over an entire circumference of the vessel body and along a plane perpendicularly intersecting the dividing wall.

Abstract: A hexagonal single crystal wafer is produced from a hexagonal single crystal ingot. A separation start point is formed by setting a focal point of a laser beam inside the ingot at a predetermined depth from the upper surface of the ingot, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot while relatively moving the focal point and the ingot to thereby form a modified layer parallel to the upper surface of the ingot and form cracks extending from the modified layer along a c-plane, thus forming a separation start point. The focal point is indexed by relatively moving the focal point in the direction where an off angle is formed and the c-plane is inclined downward.

Abstract: A wafer producing method for producing a hexagonal single crystal wafer from a hexagonal single crystal ingot, including a separation start point forming step of setting the focal point of a laser beam inside the ingot at a predetermined depth from the ingot's upper surface, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam while relatively moving the focal point and the ingot to thereby form: (i) a modified layer parallel to the ingot's upper surface, and (ii) cracks extending from the modified layer, thus forming a separation start point. The laser beam is applied to form the modified layer in a condition where the relation of ?0.3?(d?x)/d?0.5 holds, where d is the diameter of a focused spot of the laser beam and x is the spacing between adjacent focused spots of the laser beam.

Abstract: A wafer producing method for producing a hexagonal single crystal wafer from a hexagonal single crystal ingot including a separation start point forming step of setting the focal point of a laser beam inside the ingot at a predetermined depth from the ingot's upper surface, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot while relatively moving the focal point and the ingot to thereby form: (i) a modified layer parallel to the ingot's upper surface, and (ii) cracks extending from the modified layer, thus forming a separation start point. Preferably, the laser beam includes a plurality of laser beams to be simultaneously applied to form a plurality of linear modified layers. The focal points of the laser beams are arranged with predetermined spacing in the direction of formation of an off angle.

Abstract: Provided are a matching system, a matching method, and a program that can make offerings in different services. A matching system (100) includes a matching rule generation engine (4) and an offer engine (6). The matching rule generation engine (4) generates a matching rule that associates a first user belonging to a first service with a second user belonging to a second service. The offer engine (6) offers the first user a commercial material of the second service that can be offered to the second user according to the matching rule.

Abstract: A method for producing a hexagonal single crystal wafer from a hexagonal single crystal ingot includes a separation start point forming step of setting the focal point of a laser beam inside the ingot at a predetermined depth from the upper surface of the ingot, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot while relatively moving the focal point and the ingot to thereby form a modified layer parallel to the upper surface and cracks extending from the modified layer along a c-plane in the ingot, thus forming a separation start point. The ingot is immersed in water after forming the separation start point in the ingot, and ultrasonic vibration is applied to the ingot to thereby separate a plate-shaped member corresponding to the wafer from the ingot.

Abstract: A thin plate is separated from an SiC substrate having a first surface, an opposite second surface, a c-axis extending from the first surface to the second surface, and a c-plane perpendicular to the c-axis. The thin plate is formed by epitaxial growth on the first surface of the SiC substrate. The plate is separated by a separation start point forming step of setting the focal point of a laser beam near the first surface of the SiC substrate from the second surface, and applying the laser beam to the second surface to form a modified layer parallel to the first surface and cracks extending from the modified layer along the c-plane, thus forming a separation start point. An external force is applied to the SiC substrate to separate the thin plate from the SiC substrate at the separation start point.

Abstract: A wafer is produced from a compound single crystal ingot having end surface. A separation plane is formed by setting the focal point of a laser beam inside the ingot at a predetermined depth from the end surface. The depth corresponds to the thickness of the wafer to be produced. The laser beam is applied to the end surface to form a modified layer parallel to the end surface and cracks extending from the modified layer, thus forming the separation plane. The ingot has first atoms having a larger atomic weight and second atoms having a smaller atomic weight, and the end surface of the ingot is set as a polar plane where the second atoms are arranged in forming the separation plane. After producing the wafer from the ingot, the first end surface is ground to be flattened.

Abstract: A hexagonal single crystal wafer is produced from a hexagonal single crystal ingot. A wafer producing method includes a separation start point forming step of applying a laser beam to the ingot to form a modified layer parallel to the upper surface of the ingot and cracks extending from the modified layer, thus forming a separation start point. The focal point of the laser beam is relatively moved in a first direction perpendicular to a second direction where a c-axis in the ingot is inclined by an off angle with respect to a normal to the upper surface. The off angle is formed between the upper surface and a c-plane perpendicular to the c-axis, thereby linearly forming the modified layer extending in the first direction. The laser beam is applied to the ingot with the direction of the polarization plane of the laser beam set to the first direction.

Abstract: A wafer is produced from an ingot having an end surface. The method includes an end surface measuring step of measuring undulation present on the end surface, and a separation plane forming step of setting the focal point of a laser beam inside the ingot at a predetermined depth from the end surface, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the end surface to thereby form a separation plane containing a modified layer and cracks extending from the modified layer. The height of an objective lens for forming the focal point of the laser beam is controlled so that the focal point is set in the same plane to form the separation plane, according to the numerical aperture NA of the lens, the refractive index N of the ingot, and the undulation present on the end surface.

Abstract: Disclosed herein is a wafer producing method for producing a hexagonal single crystal wafer from a hexagonal single crystal ingot. The wafer producing method includes a modified layer forming step of setting the focal point of a laser beam having a transmission wavelength to the ingot inside the ingot at a predetermined depth from the upper surface of the ingot, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot as relatively moving the focal point and the ingot to thereby form a modified layer parallel to the upper surface of the ingot and cracks extending from the modified layer. In the modified layer forming step, the focal point of the laser beam is relatively moved from a radially inside position inside the ingot toward the outer circumference of the ingot.

Abstract: A crystal wafer is produced from a hexagonal crystal ingot. A separation start point is formed by setting the focal point of a laser beam inside the ingot at a predetermined depth, which depth corresponds to the thickness of the wafer to be produced. The laser beam is applied to the upper surface of the ingot while relatively moving the focal point and the ingot to form a modified layer parallel to the upper surface of the ingot and cracks extending from the modified layer along a c-plane in the ingot, thus forming the separation start point. First the laser beam is scanned from a scanning start point to a scanning end point on the ingot. Then the laser beam is scanned from the scanning end point to the scanning start point. The first and second steps are alternately repeated to separate the cracks from the modified layer.

Abstract: A method for producing a hexagonal single crystal wafer from a hexagonal single crystal ingot includes a separation start point forming step of setting the focal point of a laser beam inside the ingot at a predetermined depth from the upper surface of the ingot, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot while relatively moving the focal point and the ingot to thereby form a modified layer parallel to the upper surface and cracks extending from the modified layer along a c-plane in the ingot, thus forming a separation start point. The ingot is immersed in water after forming the separation start point in the ingot, and ultrasonic vibration is applied to the ingot to thereby separate a plate-shaped member corresponding to the wafer from the ingot.

Abstract: A hexagonal single crystal wafer is produced from a hexagonal single crystal ingot. The wafer producing method includes a separation start point forming step of setting the focal point of a laser beam having a transmission wavelength to the ingot inside the ingot at a predetermined depth from the upper surface of the ingot. The separation start point forming step includes a first step of forming the separation start point with a first power and a second step of setting the focal point at the modified layer previously formed in the first step and then applying the laser beam to the ingot with a second power higher than the first power at an increased repetition frequency in the condition where the energy per pulse of the laser beam is the same as that in the first step, thereby separating the cracks from the modified layer.

Abstract: A hexagonal single crystal wafer is produced from a hexagonal single crystal ingot. A separation start point is formed by setting a focal point of a laser beam inside the ingot at a predetermined depth from the upper surface of the ingot, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot while relatively moving the focal point and the ingot to thereby form a modified layer parallel to the upper surface of the ingot and form cracks extending from the modified layer along a c-plane, thus forming a separation start point. The focal point is indexed by relatively moving the focal point in the direction where an off angle is formed and the c-plane is inclined downward.