Abstract: The crystal plane in the interior of the diamond substrate has a curvature higher than 0 km?1 and equal to or lower than 1500 km1 by preparing a base substrate, forming a plurality of pillar-shaped diamonds formed of diamond single crystals on one side of the base substrate, causing diamond single crystals to grow from tips of each pillar-shaped diamond, coalescing each of the diamond single crystals grown from the tips of each pillar-shaped diamond to form a diamond substrate layer, separating the diamond substrate layer from the base substrate, and manufacturing the diamond substrate from the diamond substrate layer.

Abstract: A diamond substrate is formed of diamond single crystals by preparing a base substrate; forming plural pillar-shaped diamonds formed of diamond single crystals on one side of the base substrate; causing a diamond single crystal to grow from a tip of each pillar-shaped diamond and coalescing the diamond single crystals growing from the tips of the pillar-shaped diamonds to form a diamond substrate layer; separating the diamond substrate layer from the base substrate; and manufacturing a diamond substrate from the diamond substrate layer, a shape in an in-plane direction of the diamond substrate is a circular shape or a circular shape having an orientation flat plane formed therein and has a diameter of two inches or more.

Abstract: The crystal plane in the interior of the diamond substrate has a curvature higher than 0 km?1 and equal to or lower than 1500 km?1 by preparing a base substrate, forming a plurality of pillar-shaped diamonds formed of diamond single crystals on one side of the base substrate, causing diamond single crystals to grow from tips of each pillar-shaped diamond, coalescing each of the diamond single crystals grown from the tips of each pillar-shaped diamond to form a diamond substrate layer, separating the diamond substrate layer from the base substrate, and manufacturing the diamond substrate from the diamond substrate layer.

Abstract: The crystal plane in the interior of the diamond substrate has a curvature higher than 0 km?1 and equal to or lower than 1500 km?1 by preparing a base substrate, forming a plurality of pillar-shaped diamonds formed of diamond single crystals on one side of the base substrate, causing diamond single crystals to grow from tips of each pillar-shaped diamond, coalescing each of the diamond single crystals grown from the tips of each pillar-shaped diamond to form a diamond substrate layer, separating the diamond substrate layer from the base substrate, and manufacturing the diamond substrate from the diamond substrate layer.

Abstract: A diamond substrate is formed of diamond single crystals by preparing a base substrate; forming plural pillar-shaped diamonds formed of diamond single crystals on one side of the base substrate; causing a diamond single crystal to grow from a tip of each pillar-shaped diamond and coalescing the diamond single crystals growing from the tips of the pillar-shaped diamonds to form a diamond substrate layer; separating the diamond substrate layer from the base substrate; and manufacturing a diamond substrate from the diamond substrate layer, a shape in an in-plane direction of the diamond substrate is a circular shape or a circular shape having an orientation flat plane formed therein and has a diameter of two inches or more.

Abstract: A diamond substrate is formed of diamond single crystals by preparing a base substrate; forming plural pillar-shaped diamonds formed of diamond single crystals on one side of the base substrate; causing a diamond single crystal to grow from a tip of each pillar-shaped diamond and coalescing the diamond single crystals growing from the tips of the pillar-shaped diamonds to form a diamond substrate layer; separating the diamond substrate layer from the base substrate; and manufacturing a diamond substrate from the diamond substrate layer, a shape in an in-plane direction of the diamond substrate is a circular shape or a circular shape having an orientation flat plane formed therein and has a diameter of two inches or more.

Abstract: Provided is a self-support diamond substrate made of diamond and a method for producing such a substrate. A foundation substrate is prepared, several pieces of columnar diamond made of diamond single crystal are formed over one surface of the foundation substrate, the diamond single crystal is grown from the tip of each piece of columnar diamond, each piece of diamond single crystal is brought into coalescence to form a diamond substrate layer, the diamond substrate layer is separated from the foundation substrate, and the diamond substrate is produced from the diamond substrate layer. The difference between the highest point and the lowest point in the thickness direction of the diamond substrate is more than 0 ?m and 485 ?m or less and the variation of the angle of the crystal axis over the entire surface of the diamond substrate is more than 0° and 3.00° or less.

Abstract: The crystal plane in the interior of the diamond substrate has a curvature higher than 0 km?1 and equal to or lower than 1500 km?1 by preparing a base substrate, forming a plurality of pillar-shaped diamonds formed of diamond single crystals on one side of the base substrate, causing diamond single crystals to grow from tips of each pillar-shaped diamond, coalescing each of the diamond single crystals grown from the tips of each pillar-shaped diamond to form a diamond substrate layer, separating the diamond substrate layer from the base substrate, and manufacturing the diamond substrate from the diamond substrate layer.

Abstract: A diamond substrate is formed of diamond single crystals by preparing a base substrate; forming plural pillar-shaped diamonds formed of diamond single crystals on one side of the base substrate; causing a diamond single crystal to grow from a tip of each pillar-shaped diamond and coalescing the diamond single crystals growing from the tips of the pillar-shaped diamonds to form a diamond substrate layer; separating the diamond substrate layer from the base substrate; and manufacturing a diamond substrate from the diamond substrate layer, a shape in an in-plane direction of the diamond substrate is a circular shape or a circular shape having an orientation flat plane formed therein and has a diameter of two inches or more.

Abstract: Provided is a technology capable of simply manufacturing a GaN substrate, which is constituted by a GaN crystal having a substantially uniform dislocation density distribution, without using a complicated process, at low cost and at a high yield ratio. An inside of a single crystal substrate is irradiated with a laser to form an amorphous portion on the inside of the single crystal substrate, and a GaN crystal is formed on a one surface of the single crystal substrate to prepare a GaN substrate. A dislocation density distribution over the entirety of a surface of the GaN substrate that is prepared is substantially uniform. The amorphous portion is provided in a plurality of linear patterns in a planar direction of the single crystal substrate, and in a case where a pitch between respective patterns is 0.5 mm, a volume ratio of a total volume of the amorphous portion to a volume of the single crystal substrate is 0.10% or 0.20%. In a case where the pitch between the respective patterns is 1.

Abstract: Provided is a gallium oxide single crystal and a gallium oxide single crystal substrate that can improve the luminous efficiency. In a gallium oxide single crystal 13, the dislocation density is less than or equal to 3.5×106/cm2. The gallium oxide single crystal 13 is manufactured by the EFG method. Further, the seed touch temperature in the EFG method is greater than or equal to 1930 degrees centigrade and less than or equal to 1950 degrees centigrade. A neck part 13a of the gallium oxide single crystal 13 is less than or equal to 0.8 mm. A gallium oxide single crystal substrate 21 is made of the gallium oxide single crystal 13.