A monocrystalline SiC substrate comprising a first surface and a second surface. The first surface comprises pinning regions and a device region. Each of the pinning regions is configured to provide a potential well which is capable to attract dislocations from a region surrounding said pinning region. The device region is configured to provide a part of the monocrystalline SiC substrate for manufacturing a semiconductor device. The device region is surrounded by the pinning regions, and a density of dislocations in a central portion of the device region is smaller than a density of dislocations in an edge of the device region due to the pinning regions. The pinning regions surrounding the device region attracts dislocations of the device region into the edge portion, so that the density of dislocations in the central portion is reduced. A yield of the semiconductor devices is improved.

A spool of saw wire is disclosed. The saw wire is wound on the core of the spool (718). The saw wire is made of steel wire (406) wherein two or more crimp deformations are implemented. Each of said two or more crimp deformations has a crimp direction that is perpendicular to the longitudinal axis. Each of the crimp directions is different from the other crimp directions. The saw wire on the spool comprises a number of elastic rotations per unit length applied in the elastic rotation direction. The spool with saw wire can give excellent processability in the sawing process.

One aspect of the present invention provides a composite sheet which comprises a nitride sintered body having a porous structure and a semi-cured product of a thermosetting resin composition impregnated into the nitride sintered body, the line roughness Rz specified by JIS B 0601:2013 of at least one main surface being 10 m or less.

Provided is an indium phosphide substrate, a semiconductor epitaxial wafer, and a method for producing an indium phosphide substrate, which can satisfactorily suppress warpage of the back surface of the substrate. The indium phosphide substrate includes a main surface for forming an epitaxial crystal layer and a back surface opposite to the main surface, wherein the back surface has a WARP value of 3.5 m or less, as measured with the back surface of the indium phosphide substrate facing upward.

Provided is an indium phosphide substrate, a semiconductor epitaxial wafer, and a method for producing an indium phosphide substrate, which can satisfactorily suppress warpage of the back surface of the substrate. The indium phosphide substrate includes a main surface for forming an epitaxial crystal layer and a back surface opposite to the main surface, wherein the back surface has a BOW value of 2.0 to 2.0 m, as measured with the back surface of the indium phosphide substrate facing upward.

A pressing head of the ingot slicing apparatus includes: a head main body in which a plurality of pneumatic supply ports configured to supply compressed air are formed so that pressure on each portion of the pressing head is separately controlled; pressing units installed on a lower end of the head main body, located to correspond to the pneumatic supply ports, and each configured to apply pressure to a side surface of an ingot by the compressed air supplied through each of the pneumatic supply ports; pneumatic correction units each installed on a lower surface of each of the pressing units and configured to control a pressure deviation between the plurality of pressing units; an adhesive plate installed to be in contact with lower side surfaces of the pneumatic correction units so that a lower surface of the adhesive plate is in direct contact with and presses the side surface of the ingot; and a coupling support unit configured to couple and support the head main body, the pressing units, the pneumatic correction units, and the adhesive plate.

A spool of saw wire is disclosed. The saw wire is wound on the core of the spool (718). The saw wire is made of steel wire (406) wherein two or more crimp deformations are implemented. Each of said two or more crimp deformations has a crimp direction that is perpendicular to the longitudinal axis. Each of the crimp directions is different from the other crimp directions. The saw wire on the spool comprises a number of elastic rotations per unit length applied in the elastic rotation direction. The spool with saw wire can give excellent processability in the sawing process.

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 method produces wafers from a cylindrical ingot of semiconductor material having an axis and an indexing notch in an outer surface of the cylindrical ingot and parallel to the axis. The method includes, in the order specified: (a) simultaneous removal of a multiplicity of sliced wafers from the cylindrical ingot by multi-wire slicing in the presence of a cutting agent; (b) etching of the sliced wafers with an alkaline etchant in an etching bath at a temperature of 20? C. to 50? C. and for a residence time, such that the material removed from each of the sliced wafers is less than 5/1000 of an initial wafer thickness; and (c) grinding of the etched wafers by simultaneous double-disk grinding using an annular abrasive covering.

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 multiple grooved rollers, the method including feeding a workpiece to the wire row for slicing while allowing the fixed abrasive grain wire to reciprocatively travel in an axial direction thereof, thereby slicing the workpiece at multiple positions aligned in an axial direction of the workpiece simultaneously. The method includes: supplying a coolant for workpiece slicing onto the wire row when the workpiece is sliced with the fixed abrasive grain wire; and supplying a coolant for workpiece drawing, which differs from and has a higher viscosity than the coolant for workpiece slicing, onto the wire row when the workpiece is drawn out from the wire row after the slicing of the workpiece.