Presented herein is a diamond comprising a table, a crown, a girdle, a pavilion, and a culet. The table is rectangular, having a length and a width. The table includes a first side, adjacent to a second side, adjacent to a third side, and adjacent to a fourth side. The first side of the table is directly connected with a first facet of the girdle. The second side of the table is directly connected with a second facet of the girdle. The crown includes a plurality of facets connecting the third side and the fourth side of the table to the girdle. The pavilion is connected to the girdle. The culet is positioned directly below a point having a 1% deviation from the center of the girdle.

A cutting apparatus includes a cassette table on which a first cassette in which a frame unit, ring-shaped frame and wafer are housed, and a second cassette in which a simple wafer is housed. A first conveying unit having a first frame holding part holds the ring-shaped frame of the frame unit withdrawn from the first cassette and conveys the frame unit to a chuck table. A first wafer holding part holds the simple wafer withdrawn from the second cassette and conveys the simple wafer to the chuck table. A cutting unit cuts the wafer, and a second conveying unit conveys the frame unit from the chuck table to a cleaning unit. A second wafer holding part holds the cut simple wafer and conveys it from the chuck table to the cleaning unit.

An ultrasonic wave is applied to an upper surface of an ingot via a liquid layer, in a state in which an outer circumferential region of a lower surface of the ingot is sucked. A lower side around an outer circumferential arc-shaped portion of the lower surface of the ingot is open so that liquid that serves as a medium of the ultrasonic wave does not collect around the outer circumferential arc-shaped portion of the lower surface of the ingot. As a result, a peel-off layer formed in the ingot is not immersed in liquid when an ultrasonic wave is applied to the upper surface of the ingot via the liquid layer. Consequently, even when the ingot becomes thin, the ingot can be separated at the peel-off layer, and a wafer can be peeled off from the ingot.

A silicon wafer forming method includes: a block ingot forming step of cutting a silicon ingot to form block ingots; a planarizing step of grinding an end face of the block ingot to planarize the end face; a separation layer forming step of applying a laser beam of such a wavelength as to be transmitted through silicon to the block ingot, with a focal point of the laser beam positioned in the inside of the block ingot at a depth from the end face of the block ingot corresponding to the thickness of the wafer to be formed, to form a separation layer; and a wafer forming step of separating the silicon wafer to be formed from the separation layer.

A method of separating a wafer into at least two thinner wafers includes a pressing member placing step of placing a pressing member that is transmissive of a wavelength of a laser beam on a first surface of the wafer such that the pressing member is pressed against the first surface of the wafer, a separation initiating point forming step of forming a separation initiating point in the wafer by applying the laser beam whose wavelength is transmittable through the wafer to the wafer while positioning a focused spot of the laser beam within the wafer and moving the focused spot and the wafer relatively to each other along a first direction, and an indexing feed step of moving the focused spot and the wafer relatively to each other along a second direction perpendicular to the first direction.

A glass plate bend-breaking machine for a glass plate includes a supporting mechanism by which a glass plate with a predetermined bend-breaking line as a cut line formed on an upper surface, i.e., one surface, thereof is supported at a lower surface, i.e., another surface, of the glass plate; and press-breaking devices and for press-breaking the glass plate along the predetermined bend-breaking line. Each of the press-breaking devices has a pressing body for simultaneously pressing a plurality of parts and along the predetermined bend-breaking line on the upper surface of the glass plate at the time of press-breaking the glass plate along the predetermined bend-breaking line at each of press-breaking positions on the glass plate.

A method for manufacturing an ingot block in which an ingot of a silicon single crystal pulled up by a Czochralski process is cut and subjected to outer periphery grinding to manufacture an ingot block of the silicon single crystal, the method including: a step of measuring a radial center position of the ingot at one or more locations along a longitudinal direction of the ingot, a step of setting a reference position at which an offset amount of the measured radial center position of the ingot is equal to or less than a predetermined eccentricity amount, a step of cutting the ingot into the ingot blocks based on the set reference position, and a step of performing outer periphery grinding on each of the cut ingot blocks.

A process of forming a non-optically detectable authentication marking (210,320, 410,535) in a diamond (200,300). Authentication marking (210,320,410,535) is formed adjacent the outer surface of an article formed from a diamond material having intrinsic optical centers. Method includes the step of applying an image of predesigned authentication marking(210,320,410,535) to a region (201,310,530) of a diamond (200,300) at or adjacent the surface of the diamond (200,300) by way of a direct laser writing; wherein the fluorescence background of the diamond material from intrinsic optical center is suppressed by authentication marking(210,320, 410, 535) under fluorescent imaging, such that the non-optically detectable identifiable authentication marking (210,320,410,535) is viewable against the fluorescence background at the region (201,310,530) of the diamond (200,300) where the authentication marking (210,320,410,535) is applied.

A tape is stuck to the front surface of a workpiece in such a manner that the direction in which the stretch rate becomes the lowest when a predetermined force is applied to the tape is non-parallel to each of multiple planned dividing lines extending in a lattice manner. In this case, each of the multiple planned dividing lines does not extend along the direction perpendicular to this direction. This can reduce the ratio of the region to which the tape does not stick in the front surface of the workpiece in the vicinity of the boundary between each of the multiple planned dividing lines and a region in which a device is formed and suppress deterioration of the processing quality when the workpiece is divided from the back surface side by a cutting blade.

A method of splitting a semiconductor work piece includes: forming a separation zone within the semiconductor work piece, wherein forming the separation zone comprises modifying semiconductor material of the semiconductor work piece at a plurality of targeted positions within the separation zone in at least one physical property which increases thermo-mechanical stress within the separation zone relative to a remainder of the semiconductor work piece, wherein modifying the semiconductor material in one of the targeted positions comprises focusing at least two laser beams to the targeted position; and applying an external force or stress to the semiconductor work piece such that at least one crack propagates along the separation zone and the semiconductor work piece splits into two separate pieces. Additional work piece splitting techniques and techniques for compensating work piece deformation that occurs during the splitting process are also described.