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.

A method for manufacturing a solar cell, a method for manufacturing a monocrystalline silicon wafer and a photovoltaic module. The method for manufacturing a monocrystalline silicon wafer includes: providing a monocrystalline silicon rod; squaring the monocrystalline silicon rod to form a quasi-square silicon rod with quasi-square cross-section having an arc, a length of the arc being not less than 15 mm; slicing the quasi-square silicon rod to form at least one quasi-square silicon wafer having the arc. The method for manufacturing at least one solar cell includes: using the method described above to obtain a quasi-square silicon wafer having an arc; forming a first solar cell by processing the quasi-square silicon wafer; scribing the first solar cell to obtain a square-shaped sub-solar cell and at least one strip-shaped sub-solar cell. The above methods improve the utilization rate of the monocrystalline silicon rod and reduce production cost.

A method for manufacturing a solar cell, a method for manufacturing a monocrystalline silicon wafer and a photovoltaic module. The method for manufacturing a monocrystalline silicon wafer includes: providing a monocrystalline silicon rod; squaring the monocrystalline silicon rod to form a quasi-square silicon rod with quasi-square cross-section having an arc, a length of the arc being not less than 15 mm; slicing the quasi-square silicon rod to form at least one quasi-square silicon wafer having the arc. The method for manufacturing at least one solar cell includes: using the method described above to obtain a quasi-square silicon wafer having an arc; forming a first solar cell by processing the quasi-square silicon wafer; scribing the first solar cell to obtain a square-shaped sub-solar cell and at least one strip-shaped sub-solar cell. The above methods improve the utilization rate of the monocrystalline silicon rod and reduce production cost.

A peeling apparatus includes a holding table that holds an ingot, a water supply unit that forms a layer of water on an upper surface of the ingot, an ultrasonic unit that applies an ultrasonic wave to the upper surface of the ingot through the layer of water, a peeling confirmation unit that confirms peeling-off of a wafer to be manufactured, a wafer delivery unit that lowers a suction pad having a suction surface facing the upper surface of the ingot, to hold the wafer to be manufactured on the suction surface under suction, and delivers the wafer from the ingot, and a controller. After the peeling-off of the wafer is confirmed by the peeling confirmation unit, the controller positions the water supply unit, the ultrasonic unit, and the peeling confirmation unit at retracted positions and operates the wafer delivery unit to deliver the wafer from the ingot.

A process of forming a non-optically detectable authentication marking (110), includes the step of: applying a marking at a surface of a diamond (200) using a focused ion beam (FIB) writing process so as to provide a non-optically detectable authentication marking (110) which is formed by alteration in the optical characteristics of a portion of the diamond material at the outer surface of the diamond to form a marked portion; wherein the marking is optically invisible, and wherein the marking is viewable by an imaging method which provides an observable contrast between the portion of the diamond having altered optical characteristics and the non-marked portion of the diamond. The marking process can assist in the prevention of the counterfeiting of precious articles, and be of assistance in the incident of theft. A marking, a diamond, a process of viewing a marking on a diamond are further disclosed.

A process of forming a non-optically detectable authentication marking (110), includes the step of: applying a marking at a surface of a diamond (200) using a focused ion beam (FIB) writing process so as to provide a non-optically detectable authentication marking (110) which is formed by alteration in the optical characteristics of a portion of the diamond material at the outer surface of the diamond to form a marked portion; wherein the marking is optically invisible, and wherein the marking is viewable by an imaging method which provides an observable contrast between the portion of the diamond having altered optical characteristics and the non-marked portion of the diamond. The marking process can assist in the prevention of the counterfeiting of precious articles, and be of assistance in the incident of theft. A marking, a diamond, a process of viewing a marking on a diamond are further disclosed.

A method for slicing a workpiece with a wire saw which includes a wire row formed by winding a fixed abrasive grain wire having abrasive grains secured to a surface thereof around a plurality of grooved rollers, the wire being fed from one of a pair of wire reels and taken up by another, the method including feeding a workpiece to the row for slicing while allowing the wire to reciprocate and travel in an axial direction, thereby slicing the workpiece at a plurality of positions aligned in an axial direction of the workpiece simultaneously. Prior to slicing, an abrasive-grain abrading step wherein the wire is allowed to travel without slicing the workpiece, allowing the wire to rub against itself within the reels, and dressing its surface for 30 minutes or more. The method can dress a fixed abrasive grain wire at low cost and suppress thickness unevenness of wafers.

A silicon carbide wafer manufacturing method includes: a bending measuring step of measuring a first edge having the greatest degree of a bending at one surface of a silicon carbide ingot having one surface; a cutting start step of starting a cutting at a second edge having a distance of r×a along an edge of the one surface from the first edge in a direction parallel to or with a predetermined off angle with respect to the one surface through the wire saw, a cutting speed being decreased to a first cutting speed in the cutting start step; a cutting proceeding step in which the first cutting speed is substantially constant within a variation of about ±5% of the first cutting speed; and a finish step in which the cutting speed is increased from the first cutting speed and the cutting of the silicon carbide ingot is completed.

A laser system for modification of a sample to form a modified region at a target location within the sample, the target location being disposed below a surface of the sample, the laser system comprising: a laser light source configured to provide laser light; a sample holder for supporting the sample; one or more optical elements configured to direct the laser light from the laser light source into the sample when the sample is supported by the sample holder, wherein the one or more optical elements are configured to focus the laser light into the sample, and wherein the one or more optical elements includes a component configured to correct for spherical aberration caused by mismatch in refractive index at the surface of the sample through which the laser light enters the sample such that the laser light is focused at the target location within the sample, a tilt measurement device configured to measure a tilt angle of the surface of the sample relative to an optical axis of the laser light entering through the surface, and a drive mechanism for moving the sample holder and/or one or more of the optical elements based on the measured tilt angle to correct for coma aberration caused by the tilt angle.

A laser system for modification of a sample to form a modified region at a target location within the sample, the target location being disposed below a surface of the sample, the laser system comprising: a laser light source configured to provide laser light; a sample holder for supporting the sample; one or more optical elements configured to direct the laser light from the laser light source into the sample when the sample is supported by the sample holder, wherein the one or more optical elements are configured to focus the laser light into the sample, and wherein the one or more optical elements includes a component configured to correct for spherical aberration caused by mismatch in refractive index at the surface of the sample through which the laser light enters the sample such that the laser light is focused at the target location within the sample, a tilt measurement device configured to measure a tilt angle of the surface of the sample relative to an optical axis of the laser light entering through the surface, and a drive mechanism for moving the sample holder and/or one or more of the optical elements based on the measured tilt angle to correct for coma aberration caused by the tilt angle.