Abstract: A method of fabricating a polycrystalline CVD synthetic diamond wafer is disclosed. A first polycrystalline CVD synthetic diamond wafer is grown using a CVD process to a first thickness on a substrate. A second smaller wafer is cut from the polycrystalline CVD synthetic diamond wafer. The second smaller wafer is located on a carrier, and further polycrystalline CVD synthetic diamond material is grown on the second smaller wafer to a second thickness to give a polycrystalline CVD synthetic diamond material having a total thickness of the combined first and second thicknesses.

Abstract: A polycrystalline CVD synthetic diamond material is provided that has an average thermal conductivity at room temperature through a thickness of the polycrystalline CVD synthetic diamond material of between 1700 and 2400 Wm?1K?1, a thickness of at least 2.5 mm and a visible transmittance through the thickness of the polycrystalline CVD synthetic diamond of at least 25%. A wafer comprising the material is also provided, wherein at least 70% of a total area of the wafer has the properties of the polycrystalline CVD synthetic diamond material. A method for fabricating the wafer is also disclosed.

Abstract: A method of fabricating a polycrystalline CVD synthetic diamond wafer is disclosed. A first polycrystalline CVD synthetic diamond wafer is grown using a CVD process to a first thickness on a substrate. A second smaller wafer is cut from the polycrystalline CVD synthetic diamond wafer. The second smaller wafer is located on a carrier, and further polycrystalline CVD synthetic diamond material is grown on the second smaller wafer to a second thickness to give a polycrystalline CVD synthetic diamond material having a total thickness of the combined first and second thicknesses.

Abstract: A cutting element (30) includes a substrate (40); and a body of superhard polycrystalline material (34) bonded to the substrate (40) along an interface, the body of superhard polycrystalline material having a peripheral side edge (42). The body of superhard polycrystalline material has a cutting surface (34); a plurality of spaced apart cutting edges (36) extending to the cutting surface (34) through respective chamfer portions (38), the cutting edges being spaced around the peripheral side edge; a plurality of recesses/regions (48) extending from the cutting surface (34) towards the substrate, adjacent cutting edges (36) being spaced apart by a respective one of said recesses/regions (48); and a protrusion or recessed region extending from the cutting surface about a central longitudinal axis of the cutting element. A method of making such a cutting element is also disclosed.

Abstract: A cutting element (30) includes a substrate (40) having a peripheral side edge, the peripheral side edge having an associated radius of curvature; and a body of superhard polycrystalline material bonded to the substrate along an interface, the body of superhard polycrystalline material (39) having a peripheral side edge and a longitudinal axis. The body of superhard polycrystalline material (39) has a working surface (54); and a plurality of spaced apart cutting edges extending to the working surface (54) through respective chamfer portions (62), the cutting edges (61, 76) being spaced around the working surface by a further region. The cutting edges (61, 76) have an associated radius of curvature, the radius of curvature of one or more of the cutting edges being less than the radius of curvature of the substrate. A method of making such a cutting element is also disclosed.

Abstract: A polycrystalline CVD synthetic diamond material is provided that has an average thermal conductivity at room temperature through a thickness of the polycrystalline CVD synthetic diamond material of between 1700 and 2400 Wm?1K?1, a thickness of at least 2.5 mm and a visible transmittance through the thickness of the polycrystalline CVD synthetic diamond of at least 25%. A wafer comprising the material is also provided, wherein at least 70% of a total area of the wafer has the properties of the polycrystalline CVD synthetic diamond material. A method for fabricating the wafer is also disclosed.

Abstract: A method of manufacturing a composite substrate for a semiconductor device, the method comprising: depositing silicon on a surface of a synthetic diamond wafer; and treating the synthetic diamond wafer to transform the deposited silicon into silicon carbide thus forming a layer of silicon carbide on the surface of the synthetic diamond wafer, wherein the synthetic diamond wafer is selected from one of: a single crystal diamond wafer; and a polycrystalline CVD diamond wafer having a nucleation face and a growth face wherein the nucleation face comprises smaller diamond grains than the growth face, and wherein if the synthetic diamond wafer is a polycrystalline CVD diamond wafer then the silicon carbide layer is formed on the growth face of the polycrystalline CVD diamond wafer.

Abstract: Electronic field effect devices, and methods of manufacture of these electronic field effect devices are disclosed. In particular, there is disclosed an electronic field effect device which has improved electrical properties due to the formation of a highly mobile two-dimensional charge-carrier gas in a simple structure formed from diamond in combination with polar materials.

Abstract: Electronic field effect devices, and methods of manufacture of these electronic field effect devices are disclosed. In particular, there is disclosed an electronic field effect device which has improved electrical properties due to the formation of a highly mobile two-dimensional charge-carrier gas in a simple structure formed from diamond in combination with polar materials.

Abstract: Electronic field effect devices, and methods of manufacture of these electronic field effect devices are disclosed. In particular, there is disclosed an electronic field effect device which has improved electrical properties due to the formation of a highly mobile two-dimensional charge-carrier gas in a simple structure formed from diamond in combination with polar materials.

Abstract: Electronic field effect devices, and methods of manufacture of these electronic field effect devices are disclosed. In particular, there is disclosed an electronic field effect device which has improved electrical properties due to the formation of a highly mobile two-dimensional charge-carrier gas in a simple structure formed from diamond in combination with polar materials.

Abstract: Electronic field effect devices, and methods of manufacture of these electronic field effect devices are disclosed. In particular, there is disclosed an electronic field effect device which has improved electrical properties due to the formation of a highly mobile two-dimensional charge-carrier gas in a simple structure formed from diamond in combination with polar materials.

Abstract: The present invention relates to a diamond electronic device comprising a functional surface formed by a planar surface of a single crystal diamond, the planar surface of the single crystal diamond having an Rq of less than 10 nm and at least one of the following characteristics: (a) the surface has not been mechanically processed since formation by synthesis; (b) the surface is an etched surface; (c) a density of dislocations in the diamond breaking the surface is less than 400 cm?2 measured over an area greater than 0.

Abstract: The present invention relates to a diamond electronic device comprising a functional interface between two solid materials, wherein the interface is formed by a planar first surface of a first layer of single crystal diamond and a second layer formed on the first surface of the first diamond layer, the second layer being solid, non-metallic and selected from diamond, a polar material and a dielectric material, and wherein the planar first surface of the first layer of single crystal diamond has an Rq of less than 10 nm and has at least one of the following characteristics: (a) the first surface is an etched surface; (b) a density of dislocations in the first diamond layer breaking the first surface is less than 400 cm?2 measured over an area greater than 0.014 cm2; (c) a density of dislocations in the second layer breaking a notional or real surface lying within the second layer parallel to the interface and within 50 ?m of the interface is less than 400 cm?2 measured over an area greater than 0.