According to the present invention, there is provided an ingot clamp including: a clamp body configured to have a holder mounting groove and a cavity; a fixing part configured to support and fix one side of an ingot holder inserted in the holder mounting groove; a movable fixing part disposed in the cavity and the holder mounting groove and configured to press and fix the other side of the ingot holder; a cover assembly coupled with the clamp body and configured to cover the cavity; and an air supply part coupled with the cover assembly and configured to supply air into the cavity.

Semiconductor wafers having a subsurface-referenced nanotopography of the upper side surface of less than 6 nm, expressed as a maximum peak-to-valley distance on a subsurface and referenced to subsurfaces with an area content of 25 mm?25 mm, are produced from a workpiece by feeding the workpiece through a wire web tensioned between wire guide rollers and divided into wire groups, the wires producing kerfs as the wires engage the workpiece. For each of the wire groups, a placement error of the kerfs of the wire groups is used to compensate movements of the wires of the wire group as a function of the placement error, in a direction perpendicular to the running direction of the wires during feeding of the workpiece through the arrangement of wires, by activating at least one drive element.

The present invention is a method for slicing a workpiece, including: forming a wire row by a wire spirally wound between a plurality of wire guides and traveling in an axial direction, and pressing a workpiece against the wire row while supplying a processing liquid containing abrasive grains to a contact portion between the workpiece and the wire, wherein a used portion of the abrasive grains are subjected to a treatment with a mixed liquid of sulfuric acid and hydrogen peroxide, and the abrasive grains subjected to the treatment are reused for the slicing of a workpiece. This makes it possible to slice a workpiece with suppressing contamination of a wafer with metal impurities when abrasive grains are reused in slicing a workpiece by use of a wire saw.

A saw wire includes a metal wire containing rhenium-tungsten alloy. A rhenium content of the metal wire is at least 0.1 wt % and at most 10 wt % with respect to a total weight of rhenium and tungsten, an elastic modulus of the metal wire is at least 350 GPa and at most 450 GPa, a tensile strength of the metal wire is at least 3500 MPa, and a diameter of the metal wire is at most 60 m.

Semiconductor wafers are produced from a workpiece by means of a wire saw, by feeding the workpiece through an arrangement of wires tensioned between wire guide rollers and divided into wire groups, the wires moving in a running direction producing kerfs as wires engage the workpiece. For each of the wire groups, a placement error of the kerfs of the wire groups determined, and for each of the wire groups compensating movements of the wires of the wire group are induced as a function of the placement error, in a direction perpendicular to the running direction of the wires during feeding of the workpiece through the arrangement of wires, by activating at least one drive element.

Before bonding abrasive grain to a core wire, a palladium coating is applied to the surface of the abrasive grain. The palladium coating is formed as a sea on the surface of the diamond grains. In other words, the palladium coating covers the surface of the diamond grains so that the entirety thereof is continuous. Moreover, the palladium coating does not completely cover the diamond grains, and a diamond exposed portion is provided by the palladium coating not being applied on a portion thereof. The exposed diamond portion is formed as an island on the surface of the abrasive grain. In other words, a plurality of diamond exposed portions are formed as islands separated from each other.

Method for separating a polishing material, which is capable of separating and recovering cerium oxide from a used polishing material that is mainly composed of cerium oxide and a regenerated polishing material which can be obtained by the separation method. This method for separating a polishing material is characterized in that a divalent alkaline earth metal salt is added into the slurry of the used polishing material, while controlling the temperature of the slurry within the range of 10-70 DEG C., thereby causing the polishing material to aggregate under such conditions that the mother liquor has a pH of less than 10.0 as the pH is converted to one at 25 DEG C. so that the polishing material is separated from the mother liquor.

The wire saw device includes at least one wire, which is provided tightly to be capable of travelling in a direction crossing a workpiece to be cut, a workpiece holder, which is configured to hold the workpiece and to move the workpiece relative to the wire, slurry suppliers, which are configured to supply slurry to cut the workpiece from an upstream side in a travelling direction of the wire, and slurry collectors, which are configured to collect the slurry scattered due to contact with the workpiece. The slurry collector is configured to be movable in conjunction with the workpiece in the state where the slurry collector is disposed adjacent to the workpiece and also configured to be retractable with respect to the workpiece to be prevented from contacting the wire.

A wire saw apparatus including: a wire row formed of a wire wound around a plurality of wire guides and reciprocatively travels in an axial direction; a nozzle from a coolant or slurry is supplied to the wire; and a workpiece feed mechanism presses a held workpiece against the wire row, the wire saw apparatus slice the workpiece into a wafer shape by pressing the workpiece held by the workpiece feed mechanism against the wire row and feeding it for slicing while supplying the coolant or the slurry from the nozzle to the wire, the wire saw apparatus nozzle is arranged above the wire row to be orthogonal to the wire row, and windbreak plates are arranged on both left and right sides of the arranged nozzle seen from an axial direction.

Disclosed herein is a method for recovering silicon particles and abrasive grains from a wasted abrasive slurry. The method includes providing a wasted abrasive slurry that contains silicon particles, abrasive grains and a water-soluble glycol, and mixing the wasted abrasive slurry with a metal chloride solution, so as to obtain a micelle layer and a slurry layer, the micelle layer including the water-soluble glycol, and the slurry layer including the silicon particles and the abrasive grains.