For allowing a crack to progress between respective lines reliably while shortening a laser beam irradiation time, a method for processing SiC material includes allowing a laser beam to be absorbed in a cutting scheduled plane of an SiC material to form an altered pattern including a plurality of line-shaped altered regions; and cutting the SiC material along the cutting scheduled plane, wherein a plurality of line-shaped main altered regions extending in a predetermined direction, arranged at a first pitch P1 and included in altered region groups is formed, and a plurality of altered region groups is arranged at a second pitch P2 larger than the first pitch P1.

Disclosed herein is a wafer producing method for producing an SiC wafer from a single crystal SiC ingot. The wafer producing method includes a separation surface forming step of forming a separation surface composed of modified layers, cracks, and connection layers inside the ingot and a wafer separating step of separating a part of the ingot along the separation surface as an interface to thereby produce the wafer. The separation surface forming step includes a modified layer forming step of forming the modified layers and the cracks extending from the modified layers along a c-plane, and a connection layer forming step of forming the connection layers each connecting the cracks formed adjacent to each other in the thickness direction of the ingot.

A laser beam machining method and a laser beam machining device capable of cutting a work without producing a fusing and a cracking out of a predetermined cutting line on the surface of the work, wherein a pulse laser beam is radiated on the predetermined cut line on the surface of the work under the conditions causing a multiple photon absorption and with a condensed point aligned to the inside of the work, and a modified area is formed inside the work along the predetermined determined cut line by moving the condensed point along the predetermined cut line, whereby the work can be cut with a rather small force by cracking the work along the predetermined cut line starting from the modified area and, because the pulse laser beam radiated is not almost absorbed onto the surface of the work, the surface is not fused even if the modified area is formed.

A scribing wheel for scribing a brittle material-made substrate. A disc-shaped scribing-wheel base material in use is so designed that a mid-portion of a disc periphery has the largest diameter. A diamond film is formed on the periphery by a CVD method. The periphery is ground in the middle so that a plane including a circle defined by ridge line becomes perpendicular to the central axis of the scribing wheel.

A glass wafer is provided that includes a sheetlike glass substrate with an opening. The sheetlike glass substrate is configured for use in a sensor selected from a group consisting of a pressure sensor, a piezoresistive sensor, a capacitive pressure sensor, and a piezoresistive pressure sensor. The opening is defined in the glass substrate from a first surface to a second, opposite surface. The opening has a cross-sectional area that is delimited by a straight portion having a minimum length of at least 10 μm and a side face with a surface characterized by a skewness (Ssk) of at most 5.0.

A method for processing a workpiece using a pulsed laser beam includes beam shaping of the laser beam to form an elongated focus zone in the material of the workpiece. The beam shaping is carried out by using an arrangement of diffractive, reflective and/or refractive optical assemblies. The beam shaping includes focus-forming beam shaping to cause beam portions to enter at an entry angle to a beam axis of the laser beam for forming the elongated focus zone along the beam axis in the workpiece by way of interference, and phase-correcting beam shaping to counteract any influence of the interference by entrance of the laser beam into the workpiece. The method further includes setting beam parameters of the laser beam so that the material of the workpiece is modified in the elongated focus zone.

A substrate dividing method which can thin and divide a substrate while preventing chipping and cracking from occurring. This substrate dividing method comprises the steps of irradiating a semiconductor substrate 1 having a front face 3 formed with functional devices 19 with laser light while positioning a light-converging point within the substrate, so as to form a modified region including a molten processed region due to multiphoton absorption within the semiconductor substrate 1, and causing the modified region including the molten processed region to form a starting point region for cutting; and grinding a rear face 21 of the semiconductor substrate 1 after the step of forming the starting point region for cutting such that the semiconductor substrate 1 attains a predetermined thickness.

A substrate dividing method which can thin and divide a substrate while preventing chipping and cracking from occurring. This substrate dividing method comprises the steps of irradiating a semiconductor substrate 1 having a front face 3 formed with functional devices 19 with laser light while positioning a light-converging point within the substrate, so as to form a modified region including a molten processed region due to multiphoton absorption within the semiconductor substrate 1, and causing the modified region including the molten processed region to form a starting point region for cutting; and grinding a rear face 21 of the semiconductor substrate 1 after the step of forming the starting point region for cutting such that the semiconductor substrate 1 attains a predetermined thickness.

A strengthened glass sheet is separated into undamaged sheet segments by mechanically scribing one or more vent lines of controlled depth into the sheet surface, the depths of the scribed lines being insufficient to effect sheet separation, and then applying a uniform bending moment across the vent lines to effect separation into multiple sheet segments, the vent lines being scribed from crack initiation sites comprising surface indentations formed proximate to the edges of the glass sheet.

Technique to provide an abrasive regeneration method which, from a used abrasive, can recover an abrasive by an efficient method and can thereafter obtain a high-purity regenerated abrasive by a simple method. This abrasive regeneration method uses an abrasive comprising at least one type of abrasive selected from diamond, boron nitride, silicon carbide, alumina, alumina zirconia, zirconium oxide and cerium oxide. The abrasive regeneration involves a slurry recovery step (A) for recovering an abrasive slurry discharged from a polishing machine, a separation and concentration step (B) for adding an alkaline earth metal salt as an inorganic salt to the recovered abrasive slurry to aggregate the abrasive, and separating and concentrating the abrasive from a mother liquor, an abrasive recovery step (C) for recovering the separated and concentrated abrasive, and a second concentration step (D) for filter-treating the concentrated abrasive.