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: 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 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 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: 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: 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: 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 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 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 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: 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: The present invention provides a cutting tool that achieves cutting with high precision. The cutting tool of the present invention includes a cutting edge composed of a polycrystalline body including high-pressure-phase hard grains that contain one or more elements selected from the group consisting of boron, carbon, and nitrogen, the polycrystalline body being formed by subjecting a non-diamond carbon material and/or boron nitride, serving as a starting material, to direct conversion sintering under ultra-high pressure and high temperature without adding a sintering aid or a catalyst, in which letting the radius of curvature of the nose of the cutting edge of the cutting tool be R1, the sintered grains constituting the polycrystalline body have an average grain size of 1.2×R1 or less and a maximum grain size of 2×R1 or less.

Abstract: The present invention provides a cutting tool that achieves cutting with high precision. The cutting tool of the present invention includes a cutting edge composed of a polycrystalline body including high-pressure-phase hard grains that contain one or more elements selected from the group consisting of boron, carbon, and nitrogen, the polycrystalline body being formed by subjecting a non-diamond carbon material and/or boron nitride, serving as a starting material, to direct conversion sintering under ultra-high pressure and high temperature without adding a sintering aid or a catalyst, in which letting the radius of curvature of the nose of the cutting edge of the cutting tool be R1, the sintered grains constituting the polycrystalline body have an average grain size of 1.2×R1 or less and a maximum grain size of 2×R1 or less.

Abstract: An electron emitting device 2 comprises an electron emitting portion 6 made of diamond. At an electron emission current value of 10 ?A or more, a deviation of the electron emission current value over one hour is within ±20% in the electron emitting device 2. The number of occurrence of step-like noise changing the electron emission current value stepwise is once or less per 10 minutes.

Abstract: The present invention relates to an electron emitting device having a structure for efficiently emitting electrons. The electron emitting device has a substrate comprised of an n-type diamond, and a pointed projection provided on the substrate. The projection comprises a base provided on the substrate side, and an electron emission portion provided on the base and emitting electrons from the tip thereof. The base is comprised of an n-type diamond. The electron emission portion is comprised of a p-type diamond. The length from the tip of the projection (electron emission portion) to the interface between the base and the electron emission portion is preferably 100 nm or less.