A joined body (10) includes an optical material (11) and a cooling material (12) that are capable of transmitting light and are joined together. At a joining interface between the optical material (11) and the cooling material (12), the joined body (10) is capable of transmitting light, and also an atom contained in the optical material (11) diffusively enters the cooling material (12) in such a degree that an interference fringe is not generated in the joined body (10). A diffusive entry length of an atom contained in the optical material (11) into the cooling material (12) may be in a range from approximately 1.0 nm to approximately 10 μm.

A joined body (10) includes an optical material (11) and a cooling material (12) that are capable of transmitting light and are joined together. At a joining interface between the optical material (11) and the cooling material (12), the joined body (10) is capable of transmitting light, and also an atom contained in the optical material (11) diffusively enters the cooling material (12) in such a degree that an interference fringe is not generated in the joined body (10). A diffusive entry length of an atom contained in the optical material (11) into the cooling material (12) may be in a range from approximately 1.0 nm to approximately 10 μm.

A method for producing a layer of solid material includes: providing a solid body having opposing first and second surfaces, the second surface being part of the layer of solid material; generating defects by means of multiphoton excitation caused by at least one laser beam penetrating into the solid body via the second surface and acting in an inner structure of the solid body to generate a detachment plane, the detachment plane including regions with different concentrations of defects; providing a polymer layer on the solid body; and generating mechanical stress in the solid body such that a crack propagates in the solid body along the detachment plane and the layer of solid material separates from the solid body along the crack.

Provided are a diamond composite body capable of shortening a separation time for separating a substrate and a diamond layer, the substrate, and a method for manufacturing a diamond, as well as a diamond obtained from the diamond composite body and a tool including the diamond. The diamond composite body includes a substrate including a diamond seed crystal and having grooves in a main surface, a diamond layer formed on the main surface of the substrate, and a non-diamond layer formed on a substrate side at a constant depth from an interface between the substrate and the diamond layer.

Provided are a diamond composite body capable of shortening a separation time for separating a substrate and a diamond layer, the substrate, and a method for manufacturing a diamond, as well as a diamond obtained from the diamond composite body and a tool including the diamond. The diamond composite body includes a substrate including a diamond seed crystal and having grooves in a main surface, a diamond layer formed on the main surface of the substrate, and a non-diamond layer formed on a substrate side at a constant depth from an interface between the substrate and the diamond layer.

Provided are a method of manufacturing a ring-shaped member and the ring-shaped member. A method of manufacturing a ring-shaped member to be placed in a process chamber of a substrate processing apparatus includes arranging one silicon member and another silicon member to cause one abutting surface of the one silicon member and another abutting surface of the other silicon member to abut on each other, heating the one abutting surface and the other abutting surface through optical heating to melt silicon on a surface of the one abutting surface and silicon on a surface of the other abutting surface such that silicon melt is caused to flow into a gap between the one abutting surface and the other abutting surface, and cooling the one abutting surface and the other abutting surface to crystallize the silicon melt forming a silicon adhesion part.

Provided are a method of manufacturing a ring-shaped member and the ring-shaped member. A method of manufacturing a ring-shaped member to be placed in a process chamber of a substrate processing apparatus includes arranging one silicon member and another silicon member to cause one abutting surface of the one silicon member and another abutting surface of the other silicon member to abut on each other, heating the one abutting surface and the other abutting surface through optical heating to melt silicon on a surface of the one abutting surface and silicon on a surface of the other abutting surface such that silicon melt is caused to flow into a gap between the one abutting surface and the other abutting surface, and cooling the one abutting surface and the other abutting surface to crystallize the silicon melt forming a silicon adhesion part.

A SiC single crystal, wherein difference between the curving amount of the atomic arrangement surface on the cut surface cut along the <1-100> direction through the center in plan view and the curving amount of the atomic arrangement surface on the cut surface cut along the <11-20> direction that passes through the center of view and is perpendicular to the <1-100> direction is 60 μm or less.

A bonded body includes a supporting substrate; a piezoelectric material substrate composed of a material selected from the group consisting of lithium niobate, lithium tantalate and lithium niobate-lithium tantalate; and a bonding layer bonding the supporting substrate and the piezoelectric material substrate and contacting a main surface of the piezoelectric material substrate. The bonding layer includes a void extending from the piezoelectric material substrate toward the supporting substrate. A ratio (t2/t1) of a width t2 at an end of the void on a side of the supporting substrate with respect to a width t1 at an end of the void on a side of the piezoelectric material substrate is 0.8 or lower.

A bonded body includes a supporting substrate; a piezoelectric material substrate composed of a material selected from the group consisting of lithium niobate, lithium tantalate and lithium niobate-lithium tantalate; and a bonding layer bonding the supporting substrate and the piezoelectric material substrate and contacting a main surface of the piezoelectric material substrate. The bonding layer includes a void extending from the piezoelectric material substrate toward the supporting substrate. A ratio (t2/t1) of a width t2 at an end of the void on a side of the supporting substrate with respect to a width t1 at an end of the void on a side of the piezoelectric material substrate is 0.8 or lower.