Abstract: Provided is a method for manufacturing a single-crystal diamond, the method including the steps of: forming a protective film on at least a part of a surface of an auxiliary plate; preparing a diamond seed crystal substrate; disposing an auxiliary plate with a protective film that has the protective film formed on the auxiliary plate, and a diamond seed crystal substrate in a chamber; and growing a single-crystal diamond on a principal surface of the diamond seed crystal substrate by a chemical vapor deposition method while introducing a carbon-containing gas into the chamber.

Abstract: A single-crystal diamond includes a pair of main surfaces facing each other, an impurity concentration being changed along a first direction in each of the main surfaces.

Abstract: A diamond die includes a diamond provided with a hole for drawing a wire material, the diamond being a CVD single-crystal diamond, an axis of the hole being inclined relative to a normal direction of a crystal plane of the diamond.

Abstract: A method of manufacturing a diamond substrate includes: forming an ion implantation layer at a side of a main surface of a diamond seed substrate by implanting ions into the main surface of the diamond seed substrate; producing a diamond structure by growing a diamond growth layer by a vapor phase synthesis method on the main surface of the diamond seed substrate, after implanting the ions; and performing heat treatment on the diamond structure. The performed heat treatment causes the diamond structure to be separated along the ion implantation layer into a first structure including the diamond seed substrate and failing to include the diamond growth layer, and a diamond substrate including the diamond growth layer. Thus, the method of manufacturing a diamond substrate is provided that enables a diamond substrate with a large area to be manufactured in a short time and at a low cost.

Abstract: A single crystal diamond (10) is provided as a single crystal diamond into which a defect portion (11) is introduced. The defect portion (11) can be detected by a phase difference occurring when the single crystal diamond (10) is irradiated with circularly polarized light. In the single crystal diamond (10), a maximum value of average values of the phase differences measured within a measurement region (M) formed in a shape of a square having a side length of 1 mm is 30 nm or more.

Abstract: A single crystal diamond has a surface. In the single crystal diamond, a measurement region is defined in the surface, the measurement region includes a portion exhibiting a transmittance that is highest in the single crystal diamond and a portion exhibiting a transmittance that is lowest in the single crystal diamond, the measurement region has a plurality of square regions that are continuously arranged and each have a side having a length of 0.2 mm, and an average value of transmittances in each of the plurality of square regions is measured, wherein assuming that the average value of the transmittances in one square region is defined as T1 and the average value of the transmittances in another square region adjacent to the one square region is defined as T2, a relation of ((T1?T2)/((T1+T2)/2)×100)/0.2?20 (%/mm) is satisfied throughout the measurement region.

Abstract: A method for manufacturing a semiconductor substrate according to the present invention includes preparing a seed substrate containing a semiconductor material, forming an ion implanted layer at a certain depth from a front surface of a main surface of the seed substrate by implanting ions into the seed substrate, growing a semiconductor layer on the main surface of the seed substrate with a vapor-phase synthesis method, and separating a semiconductor substrate including the semiconductor layer and a part of the seed substrate by irradiating the front surface of the main surface of at least any of the semiconductor layer and the seed substrate with light.

Abstract: A composite diamond body includes a diamond base material and a stable layer disposed on the diamond base material. The stable layer may have a thickness of 0.001 ?m or more and less than 10 ?m, and may include a plurality of layers. A composite diamond tool includes the composite diamond body. There are thus provided highly wear-resistant composite diamond body and composite diamond tool that are even applicable to mirror-finish planarization of a workpiece which reacts with diamond to cause the diamond to wear.

Abstract: A single-crystal diamond material has a transmittance of light with a wavelength of greater than or equal to 410 nm and less than or equal to 750 nm of less than or equal to 15% for any wavelength, and is at least either of an electrical insulator according to optical evaluation and an electrical insulator according to electrical evaluation. A criterion of the optical evaluation can be a transmittance of light with a wavelength of 10.6 ?m of greater than or equal to 1%. A criterion of the electrical evaluation can be an average resistivity of greater than or equal to 1×106 ?cm. Accordingly, a single-crystal diamond material having a low transmittance of light in the entire region of the visible light region and exhibiting a black color is provided.

Abstract: In a single-crystal diamond material, a concentration of non-substitutional nitrogen atoms is not more than 200 ppm, a concentration of substitutional nitrogen atoms is lower than the concentration of the non-substitutional nitrogen atoms, and the single-crystal diamond material has a crystal growth main surface having an off angle of not more than 20°. A perforated tool includes a single-crystal diamond die, wherein in the single-crystal diamond die, a concentration of non-substitutional nitrogen atoms is not more than 200 ppm, a concentration of substitutional nitrogen atoms is lower than the concentration of the non-substitutional nitrogen atoms, and the single-crystal diamond die has a low-index plane represented by a Miller index of not less than ?5 and not more than 5 in an integer, a perpendicular line of the low-index plane having an off angle of not more than 20° relative to an orientation of a hole for wire drawing.

Abstract: 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.

Abstract: A method of manufacturing a diamond by a vapor phase synthesis method includes: preparing a substrate including a diamond seed crystal; forming a light absorbing layer lower in optical transparency than the substrate by performing ion implantation into the substrate, the light absorbing layer being formed at a predetermined depth from a main surface of the substrate; growing a diamond layer on the main surface of the substrate by the vapor phase synthesis method; and separating the diamond layer from the substrate by applying light from a main surface of at least one of the diamond layer and the substrate to allow the light absorbing layer to absorb the light and cause the light absorbing layer to be broken up.

Abstract: In an X-ray topography image for a crystal growth main surface of a single-crystal diamond, a group of crystal defect points are gathered, each of the crystal defect points being a tip point of a crystal defect line reaching the crystal growth main surface, the crystal defect line representing a line in which a crystal defect exists. Further, in the single-crystal diamond, a plurality of crystal defect line-like gathered regions exist in parallel. In the plurality of crystal defect line-like gathered regions, groups of crystal defect points are gathered to extend in the form of lines in a direction angled by not more than 30° relative to one arbitrarily specified direction. Accordingly, a single-crystal diamond is provided which is used suitably for a cutting tool, a polishing tool, an optical component, an electronic component, a semiconductor material, and the like.

Abstract: Single crystal diamond of which hardness and chipping resistance have been improved in a balanced manner, a method for manufacturing the single crystal diamond, and a tool containing the diamond are provided. Single crystal diamond contains nitrogen atoms, and a ratio of the number of isolated substitutional nitrogen atoms in the single crystal diamond to the total number of nitrogen atoms in the single crystal diamond is not lower than 0.02% and lower than 40%.

Abstract: A method for producing a diamond single crystal includes implanting an ion other than carbon into a surface of a diamond single crystal seed substrate and thereby decreasing the transmittance of light having a wavelength of 800 nm, the surface having an off-angle of 7 degrees or less with respect to a {100} plane, and homoepitaxially growing a diamond single crystal on the ion-implanted surface of the seed substrate using a chemical vapor synthesis under synthesis conditions where the ratio NC/NH of the number of carbon-containing molecules NC to the number of hydrogen molecules NH in a gas phase is 10% or more and 40% or less, the ratio NN/NC of the number of nitrogen molecules NN to the number of carbon-containing molecules NC in the gas phase is 0.1% or more and 10% or less, and the seed substrate temperature T is 850° C. or more and less than 1000° C.

Abstract: A method for producing a diamond single crystal includes implanting an ion other than carbon into a surface of a diamond single crystal seed substrate and thereby decreasing the transmittance of light having a wavelength of 800 nm, the surface having an off-angle of 7 degrees or less with respect to a {100} plane, and homoepitaxially growing a diamond single crystal on the ion-implanted surface of the seed substrate using a chemical vapor synthesis under synthesis conditions where the ratio NC/NH of the number of carbon-containing molecules NC to the number of hydrogen molecules NH in a gas phase is 10% or more and 40% or less, the ratio NN/NC of the number of nitrogen molecules NN to the number of carbon-containing molecules NC in the gas phase is 0.1% or more and 10% or less, and the seed substrate temperature T is 850° C. or more and less than 1000° C.

Abstract: A single crystal diamond (10) is provided as a single crystal diamond into which a defect portion (11) is introduced. The defect portion (11) can be detected by a phase difference occurring when the single crystal diamond (10) is irradiated with circularly polarized light. In the single crystal diamond (10), a maximum value of average values of the phase differences measured within a measurement region (M) formed in a shape of a square having a side length of 1 mm is 30 nm or more.

Abstract: A method for producing a diamond single crystal includes implanting an ion other than carbon into a surface of a diamond single crystal seed substrate and thereby decreasing the transmittance of light having a wavelength of 800 nm, the surface having an off-angle of 7 degrees or less with respect to a {100} plane, and homoepitaxially growing a diamond single crystal on the ion-implanted surface of the seed substrate using a chemical vapor synthesis under synthesis conditions where the ratio NC/NH of the number of carbon-containing molecules NC to the number of hydrogen molecules NH in a gas phase is 10% or more and 40% or less, the ratio NN/NC of the number of nitrogen molecules NN to the number of carbon-containing molecules NC in the gas phase is 0.1% or more and 10% or less, and the seed substrate temperature T is 850° C. or more and less than 1000° C.

Abstract: A single crystal diamond has a surface. In the single crystal diamond, a measurement region is defined in the surface, the measurement region includes a portion exhibiting a transmittance that is highest in the single crystal diamond and a portion exhibiting a transmittance that is lowest in the single crystal diamond, the measurement region has a plurality of square regions that are continuously arranged and each have a side having a length of 0.2 mm, and an average value of transmittances in each of the plurality of square regions is measured, wherein assuming that the average value of the transmittances in one square region is defined as T1 and the average value of the transmittances in another square region adjacent to the one square region is defined as T2, a relation of ((T1?T2)/((T1+T2)/2)×100)/0.2?20 (%/mm) is satisfied throughout the measurement region.

Abstract: The present invention relates to a diamond n-type semiconductor in which the amount of change in carrier concentration is fully reduced in a wide temperature range. The diamond n-type semiconductor comprises a diamond substrate, and a diamond semiconductor formed on a main surface thereof and turned out to be n-type. The diamond semiconductor exhibits a carrier concentration (electron concentration) negatively correlated with temperature in a part of a temperature region in which it is turned out to be n-type, and a Hall coefficient positively correlated with temperature. The diamond n-type semiconductor having such a characteristic is obtained, for example, by forming a diamond semiconductor doped with a large amount of a donor element while introducing an impurity other than the donor element onto the diamond substrate.