A wafer processing method includes preparing a holding table having a blade clearance portion formed therein so as to correspond to a notch of a wafer, holding the wafer by the holding table so as to make the notch of the wafer correspond to the blade clearance portion of the holding table, reducing the diameter of the wafer by cutting the wafer by a cutting blade along an outer peripheral edge of the wafer in a state in which an end of the cutting blade is positioned below the holding surface of the holding table and therefore removing at least a part of the notch portion, and forming a second notch in the wafer by cutting the wafer in a thickness direction by the cutting blade along the blade clearance portion of the holding table.

Methods of recycling silicon swarf into electronic grade polysilicon or metallurgical-grade silicon are described herein are described. In an example, a method includes cutting a silicon ingot and recovering silicon swarf having a first purity from the cutting process. The recovered silicon is purified in an upgraded metallurgical silicon process to produce electronic grade polysilicon particles having a second purity higher than the first purity. The upgraded metallurgical silicon process can include dissolving the recovered silicon particles in a molten aluminum metal smelt.

Methods of recycling silicon swarf into electronic grade polysilicon or metallurgical-grade silicon are described herein are described. In an example, a method includes cutting a silicon ingot and recovering silicon swarf having a first purity from the cutting process. The recovered silicon is purified in an upgraded metallurgical silicon process to produce electronic grade polysilicon particles having a second purity higher than the first purity. The upgraded metallurgical silicon process can include dissolving the recovered silicon particles in a molten aluminum metal smelt.

Methods of recycling silicon swarf into electronic grade polysilicon or metallurgical-grade silicon are described herein are described. In an example, a method includes cutting a silicon ingot and recovering silicon swarf having a first purity from the cutting process. The recovered silicon is purified in an upgraded metallurgical silicon process to produce electronic grade polysilicon particles having a second purity higher than the first purity. The upgraded metallurgical silicon process can include dissolving the recovered silicon particles in a molten aluminum metal smelt.

A multiplicity of slices are simultaneously sliced from a workpiece during a slicing operation using a wire saw. A non-linear pitch function dTAR(WP) is selected dependent on a target thickness value function TTAR(WP), a pitch function dINI(WP) and a thickness value function TINI(WP), dTAR(WP) and adjacent grooves in the wire guide rollers are assigned a pitch at a position WP during the slicing operation, TINI(WP) slices which are obtained during a plurality of preceding slicing operations by means of the wire saw at the position WP are assigned a thickness value, dINI(WP), adjacent grooves in the wire guide rollers at the position WP are assigned a pitch during the preceding slicing operations, TTAR(WP) slices which are sliced off during the slicing operation at the position WP are assigned a target thickness value, WP denoting the axial position of the adjacent grooves with respect to the axes of the wire guide rollers.

The present invention provides a monocrystalline SiC substrate with an asymmetric shape for enhancing substrate stiffness against thermal induced deformations, the substrate comprising: a main region, and an asymmetric region located at a peripheral region of the substrate and adjacent to the main region, wherein the asymmetric region is inclined inwards, relative to the main region, to provide an asymmetric shape to the substrate. The present invention also provides a method of producing one or more substrates with an asymmetric shape, comprising: performing a multi-wire sawing process in which one or more substrates are cut with an wire-sawing web from an ingot placed on a stage, and cutting the one or more substrates with the asymmetric shape by controlling a relative movement between the wire-sawing web and the stage, the relative movement causing the wire-sawing web to describe a non-linear sawing path across the ingot to cut the asymmetric shape.

A method of manufacturing a hexagonal Group-III nitride semiconductor plate crystal using a crystal cutting wire. where the hexagonal semiconductor crystal has one principal face on one side and another principal face on an opposite side, and the hexagonal semiconductor crystal is cut by causing the crystal cutting wire to move so as to (i) divide the one principal face and the another principal face and (ii) satisfy conditions of Expressions (A) and (B):
25°<α≤90°  Expression (A); and
β=90°±5°  Expression (B) where α represents an angle formed by a c axis of the hexagonal Group-III nitride semiconductor crystal and a normal line of a crystal face cut out by the wire, and β represents an angle formed by a reference axis, which is obtained by perpendicularly projecting the c axis of the hexagonal Group-III nitride semiconductor crystal to the crystal face cut out by the wire, and a cutting direction.

A method cuts slices from workpieces using a wire saw having a wire array, which is tensioned in a plane between two wire guide rollers supported between fixed and floating bearings and having a chamber and a shell. The workpiece is fed through the wire array along a feed direction perpendicular to a workpiece axis, while simultaneously changing the shells' lengths by adjusting a temperature of the chambers with a first cooling fluid in accordance with a first correction profile specifying a change in the shells' lengths based on the depth of cut. The floating bearings are simultaneously axially moved by adjusting a temperature of the fixed bearings with a second cooling fluid in accordance with a second correction profile, which specifies a travel of the floating bearings based on the depth of cut. The first correction profile and the second correction profile are opposed to a shape deviation.

A slurry sprayer for supplying a slurry to a wire saw during ingot slicing is disclosed. The slurry sprayer includes a main body and a cover plate that is detachable from the main body for cleaning the slurry sprayer. In some embodiments, the slurry sprayer includes an adjustable support that allows the incline angle of the sprayer to be adjusted and allows the vertical and horizontal position of the slurry sprayer to be adjusted. In some embodiments, the slurry sprayer includes two feed openings to allow the slurry pressure to be more equalized across the slurry sprayer.

A method for manufacturing a wire saw apparatus including a wire supply reel; a long roller; wire guides; a wire winding reel; and a tension arm controlled to move within a control angle of ±A (°) set in advance and configured to apply tension to the wire, the method including the steps of: measuring a surface roughness Rmax of the long roller; measuring an angle a (°) of the tension arm at which the tension arm swings outside a range of the control angle set in advance while the wire is extending from the wire supply reel; calculating R1×2×A÷(|a|+A)=R2, where R1 (μm) represents the measured surface roughness Rmax of the long roller; and adjusting the surface roughness Rmax of the long roller to the calculated numerical value R2 or less. The method for manufacturing a wire saw apparatus can prevent the tension arm from greatly swinging outside the control range.