A synthetic single crystal diamond containing nitrogen atoms at a concentration of 100 ppm or more and 1500 ppm or less based on atom numbers, in which the synthetic single crystal diamond contains aggregates each composed of one vacancy and three substitutional nitrogen atoms present adjacent to the vacancy, and a Raman shift λ′ cm.sup.−1 of a peak in a first-order Raman scattering spectrum of the synthetic single crystal diamond and a Raman shift λ cm.sup.−1 of a peak in a first-order Raman scattering spectrum of a synthetic type IIa single crystal diamond containing nitrogen atoms at a concentration of 1 ppm or less based on atom numbers show a relationship of the following formula 1,

λ′−λ≥0  Formula 1.

A synthetic single crystal diamond containing nitrogen atoms at a concentration of 100 ppm or more and 1500 ppm or less based on atom numbers, in which the synthetic single crystal diamond contains aggregates each composed of one vacancy and three substitutional nitrogen atoms present adjacent to the vacancy, and a Raman shift λ′ cm.sup.−1 of a peak in a first-order Raman scattering spectrum of the synthetic single crystal diamond and a Raman shift λ cm.sup.−1 of a peak in a first-order Raman scattering spectrum of a synthetic type IIa single crystal diamond containing nitrogen atoms at a concentration of 1 ppm or less based on atom numbers show a relationship of the following formula 1,

λ′−λ≥0  Formula 1.

An artificial diamond plasma production device has a reaction chamber, a microwave emitting module, and a microwave lens. The microwave emitting module emits a circularly-polarized microwave into the reaction chamber. The microwave emitting module has a polarizing tube, a directing tube, a first waveguide, and a first linearly-polarized microwave source serially connected along a microwave traveling path. The microwave emitting module further has a second waveguide and a first matched load. The polarizing tube is configured to convert a linearly-polarized microwave into a circularly-polarized microwave or the other way round depending on traveling direction of the microwave. The directing tube has a first opening and a second opening which face toward different directions. The first waveguide is connected to the first opening. The first matched load is connected to the second opening via the second waveguide. Therefore, reflected microwave can be channeled out of the reaction chamber.

An artificial diamond plasma production device has a reaction chamber, a microwave emitting module, and a microwave lens. The microwave emitting module emits a circularly-polarized microwave into the reaction chamber. The microwave emitting module has a polarizing tube, a directing tube, a first waveguide, and a first linearly-polarized microwave source serially connected along a microwave traveling path. The microwave emitting module further has a second waveguide and a first matched load. The polarizing tube is configured to convert a linearly-polarized microwave into a circularly-polarized microwave or the other way round depending on traveling direction of the microwave. The directing tube has a first opening and a second opening which face toward different directions. The first waveguide is connected to the first opening. The first matched load is connected to the second opening via the second waveguide. Therefore, reflected microwave can be channeled out of the reaction chamber.

The present invention relates to a method for manufacturing a diamond substrate, and more particularly, to a method of growing diamond after forming a structure of an air gap having a crystal correlation with a lower substrate by heat treatment of a photoresist pattern and an air gap forming film material on a substrate such as sapphire (Al.sub.2O.sub.3). Through such a method, a process is simplified and the cost is lowered when large-area/large-diameter single crystal diamond is heterogeneously grown, stress due to differences in a lattice constant and a coefficient of thermal expansion between the heterogeneous substrate and diamond is relieved, and an occurrence of defects or cracks is reduced even when a temperature drops, such that a high-quality single crystal diamond substrate may be manufactured and the diamond substrate may be easily self-separated from the heterogeneous substrate.

A method of manufacturing a diamond substrate includes: a step of placing a laser condensing unit 190 configured to condense laser light B so as to face an upper surface 10a of a block 10 of single crystal diamond; and a step of forming a modified layer 20, which includes a processing mark 21b of graphite and a crack 22b extending along a surface (111) around the processing mark 21b, along the surface (111) of the single crystal diamond at a predetermined depth from an upper surface of the block by radiating the laser light B on the upper surface 10a of the block 10 from the laser condensing unit 190 under predetermined conditions and condensing the laser light B inside the block 10, and moving the laser condensing unit 190 and the block 10 in a relative manner two-dimensionally.

Disclosed herein are systems and methods for synthesizing a diamond using a diamond synthesis machine. A processor receives a plurality of images of a diamond during synthesis within a diamond synthesis machine, each of the plurality of images captured within a time period. The processor executes a diamond state prediction machine learning model using the plurality of images to obtain a predicted data object, the predicted data object indicating a predicted state of the diamond within the diamond synthesis machine at a time subsequent to the time period. The processor detects a predicted defect, a number of defects, defect types, and/or sub-features of such defects and/or other characteristics (e.g., a predicted shape, size, and/or other properties of predicted contours for the diamond and/or pocket holder) of the predicted state of the diamond. The processor adjusts operation of the diamond synthesis machine.

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.

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.

A method for forming at least one freestanding microstructure on a diamond crystal includes the step of removing material from the diamond crystal so as to form a structured surface, wherein the removing of the material includes creating at least two trenches, each trench having a bottom and two side walls and wherein adjacent side walls of the at least two trenches form side walls of the structured surface. The method also includes the steps of depositing at least one masking layer on the structured surface, removing at least a portion of the at least one masking layer from the bottom of each of the at least two trenches, removing additional material from the diamond crystal at least along the side walls so as to deepen the trenches, and undercutting the diamond crystal so as to form the freestanding microstructure.