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.

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, a step of forming a modified layer 20, which includes a processing mark 21 of graphite and a crack 22b extending along a surface (111) around the processing mark 21, in a partial region of the upper surface 10a of the block 10 along the surface (111) of the single crystal diamond, along the surface (111) of the single crystal diamond at a predetermined depth from the upper surface 10a of the block 10 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, and a step of forming a cleavage plane 25 at the predetermined depth of the remaining region of the upper surface 10a of the block 10 by spontaneously propagating cleavage from the modified layer 20.

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, a step of forming a modified layer 20, which includes a processing mark 21 of graphite and a crack 22b extending along a surface (111) around the processing mark 21, in a partial region of the upper surface 10a of the block 10 along the surface (111) of the single crystal diamond, along the surface (111) of the single crystal diamond at a predetermined depth from the upper surface 10a of the block 10 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, and a step of forming a cleavage plane 25 at the predetermined depth of the remaining region of the upper surface 10a of the block 10 by spontaneously propagating cleavage from the modified layer 20.

Provided is a synthetic single-crystal diamond containing nitrogen. In an X-ray absorption fine structure thereof, a ratio I.sub.405/I.sub.412 between an intensity I.sub.405 of a peak which appears at an energy of 405±1 eV and has a full width at ¾ maximum of 3 eV or more and an intensity I.sub.412 of a peak which appears at an energy of 412±2 eV is less than 1.5

Provided is a synthetic single crystal diamond containing nitrogen atoms at a concentration of more than 600 ppm and 1500 ppm or less. The Raman shift λ′ (cm.sup.−1) of a peak in a primary Raman scattering spectrum of the synthetic single crystal diamond and the Raman shift λ (cm.sup.−1) of a peak in a primary Raman scattering spectrum of a synthetic type IIa single crystal diamond containing nitrogen atoms at a content of 1 ppm or less satisfy the following expression (1):
λ′−λ≥−0.10  (1).

Provided is a synthetic single crystal diamond containing nitrogen atoms at a concentration of more than 600 ppm and 1500 ppm or less. The Raman shift λ′ (cm.sup.−1) of a peak in a primary Raman scattering spectrum of the synthetic single crystal diamond and the Raman shift λ (cm.sup.−1) of a peak in a primary Raman scattering spectrum of a synthetic type IIa single crystal diamond containing nitrogen atoms at a content of 1 ppm or less satisfy the following expression (1):
λ′−λ≥−0.10  (1).

A method for the production of a graphene layer structure having from 1 to 100 graphene layers, the method comprising providing a substrate having a thermal resistance equal to or greater than that of sapphire, on a heated susceptor in a reaction chamber, the chamber having a plurality of cooled inlets arranged so that, in use, the inlets are distributed across the substrate and have a constant separation from the substrate, supplying a flow comprising a precursor compound through the inlets and into the reaction chamber to thereby decompose the precursor compound and form graphene on the substrate, wherein the inlets are cooled to less than 100° C., preferably 50 to 60° C., and the susceptor is heated to a temperature of at least 50° C. in excess of a decomposition temperature of the precursor, using a laser to selectively ablate graphene from the substrate, wherein the laser has a wavelength in excess of 600 nm and a power of less than 50 Watts.

A method for the production of a graphene layer structure having from 1 to 100 graphene layers, the method comprising providing a substrate having a thermal resistance equal to or greater than that of sapphire, on a heated susceptor in a reaction chamber, the chamber having a plurality of cooled inlets arranged so that, in use, the inlets are distributed across the substrate and have a constant separation from the substrate, supplying a flow comprising a precursor compound through the inlets and into the reaction chamber to thereby decompose the precursor compound and form graphene on the substrate, wherein the inlets are cooled to less than 100° C., preferably 50 to 60° C., and the susceptor is heated to a temperature of at least 50° C. in excess of a decomposition temperature of the precursor, using a laser to selectively ablate graphene from the substrate, wherein the laser has a wavelength in excess of 600 nm and a power of less than 50 Watts.

A structure includes a semiconductor substrate, and a polycrystalline resistor region over the semiconductor substrate. The polycrystalline resistor region includes a semiconductor material in a polycrystalline morphology. A dopant-including polycrystalline region is between the polycrystalline resistor region and the semiconductor substrate.

Embodiments described herein relate generally to the large scale production of functionalized graphene. In some embodiments, a method for producing functionalized graphene includes combining a crystalline graphite with a first electrolyte solution that includes at least one of a metal hydroxide salt, an oxidizer, and a surfactant. The crystalline graphite is then milled in the presence of the first electrolyte solution for a first time period to produce a thinned intermediate material. The thinned intermediate material is combined with a second electrolyte solution that includes a strong oxidizer and at least one of a metal hydroxide salt, a weak oxidizer, and a surfactant. The thinned intermediate material is then milled in the presence of the second electrolyte solution for a second time period to produce functionalized graphene.