A method for washing an aluminum nitride single crystal substrate, the aluminum nitride single crystal substrate including: an aluminum-polar face; and a nitrogen-polar face opposite to the aluminum-polar face, the method including: (a) scrubbing a surface of the nitrogen-polar face.

A method for washing an aluminum nitride single crystal substrate, the aluminum nitride single crystal substrate including: an aluminum-polar face; and a nitrogen-polar face opposite to the aluminum-polar face, the method including: (a) scrubbing a surface of the nitrogen-polar face.

There is provided a Group-III element nitride semiconductor substrate including a first surface and a second surface, in which even when devices to be produced on the first surface are increased in size, variations in device characteristics between the devices in the same substrate are suppressed. A Group-III element nitride semiconductor substrate includes a first surface and a second surface. The Group-III element nitride semiconductor substrate satisfies at least one of the following items (1) to (3): (1) The main surface has a maximum height Wz of a surface waviness profile of 150 nm or less; (2) The main surface has a root mean square height Wq of the surface waviness profile of 25 nm or less; (3) The main surface has an average length WSm of surface waviness profile elements of 0.5 mm or more.

Provided are a method of polishing a silicon wafer and a method of producing a silicon wafer which can reduce the formation of step-forming microdefects on a silicon wafer. The method includes: a double-side polishing step of performing polishing on front and back surfaces of a silicon wafer; a notch portion polishing step of performing polishing on a beveled portion of a notch portion of the silicon wafer after the double-side polishing step; a peripheral beveled portion polishing step of performing polishing on the beveled portion on the periphery of the silicon wafer other than the beveled portion of the notch portion after the notch portion polishing step; and a finish polishing step of performing finish polishing on the front surface of the silicon wafer after the peripheral beveled portion polishing step. The notch portion polishing step is performed in a state where the front surface is wet with water.

The present embodiments relate to a method for manufacturing a two-dimensional material using a top-down method, the method includes the steps of preparing a bulk crystal, forming a metal layer on the bulk crystal, and then attaching a thermal release tape on the metal layer, exfoliating a two-dimensional material to which the metal layer and the thermal release tape have been attached from the bulk crystal, transferring the two-dimensional material to which the metal layer and the thermal release tape have been attached onto a substrate, and removing the thermal release tape and the metal layer from the substrate onto which the two-dimensional material has been transferred.

The present embodiments relate to a method for manufacturing a two-dimensional material using a top-down method, the method includes the steps of preparing a bulk crystal, forming a metal layer on the bulk crystal, and then attaching a thermal release tape on the metal layer, exfoliating a two-dimensional material to which the metal layer and the thermal release tape have been attached from the bulk crystal, transferring the two-dimensional material to which the metal layer and the thermal release tape have been attached onto a substrate, and removing the thermal release tape and the metal layer from the substrate onto which the two-dimensional material has been transferred.

An SiC ingot forming method includes: a holding step of holding by a chuck table a cut section of a primitive SiC ingot cut from an SiC ingot growth base; a planarization step of grinding an end surface of the primitive SiC ingot held by the chuck table, to planarize the end surface; a c-plane detection step of detecting a c-plane of the primitive SiC ingot from the planarized end surface; a first end surface forming step of grinding the planarized end surface, to form a first end surface inclined at an off angle relative to the c-plane; and a second end surface forming step of holding the first end surface by the chuck table and grinding the cut section of the primitive SiC ingot in parallel to the first end surface, to form a second end surface.

An SiC ingot forming method includes: a holding step of holding by a chuck table a cut section of a primitive SiC ingot cut from an SiC ingot growth base; a planarization step of grinding an end surface of the primitive SiC ingot held by the chuck table, to planarize the end surface; a c-plane detection step of detecting a c-plane of the primitive SiC ingot from the planarized end surface; a first end surface forming step of grinding the planarized end surface, to form a first end surface inclined at an off angle relative to the c-plane; and a second end surface forming step of holding the first end surface by the chuck table and grinding the cut section of the primitive SiC ingot in parallel to the first end surface, to form a second end surface.

A silicon carbide wafer has one surface and the other surface opposite to the one surface. An average Rmax roughness of the one surface is 2.0 nm or less, and an average Ra roughness of the one surface is 0.1 nm or less. An edge region is a region in which a distance from an edge of the silicon carbide wafer toward a center is 5% to 75% of a radius of the silicon carbide wafer, and a central region is a region having a radius of 25% of the radius of the silicon carbide wafer at the center of the silicon carbide wafer. A difference between an average Rmax roughness of the edge region of the one surface and an average Rmax roughness of the central region of the one surface is 0.01 nm to 0.5 nm.

Provided is a particulate phosphor including a single crystal having a composition represented by a compositional formula (Y.sub.1-x-y-zLu.sub.xGd.sub.yCe.sub.z).sub.3+aAl.sub.5−aO.sub.12 (0≤x≤0.9994, 0≤y≤0.0669, 0.001≤z≤0.004, −0.016≤a≤0.315) and a particle diameter (D50) of not less than 20 μm. Also provided is a light-emitting device including a phosphor-including member that includes the phosphor and a sealing member including a transparent inorganic material sealing the phosphor or a binder including an inorganic material binding particles of the phosphor, and a light-emitting element that emits a blue light for exciting the phosphor.