A novel composite diamond film comprising of a relatively thick layer of UNCD (Ultrananocrystalline Diamond) with a Young's modulus of less than 900 GPa and a relatively thin MCD (microcrystalline diamond) outermost layer with a Young's modulus of greater than 900 GPa, has been shown to exhibit superior delamination resistance under extreme shear stress. It is hypothesized that this improvement is due to a combination of stress relief by the composite film with a slightly softer UNCD layer, a disruption of the fracture mechanism through the composite layer(s), and the near ideal chemical and thermal expansion coefficient match between the two diamond layers. The combination of a thick but softer underlying UNCD layer with a thin but harder overlying MCD layer provides an excellent compromise between the low deposition cost and smoothness of UNCD with the extreme hardness and unparalleled chemical, electrochemical and immunological inertness of even a thin layer of MCD. The MCD layer's roughness is minimized and its adhesion maximized by the use of a thin layer of MCD and its deposition on the smooth surface of the chemically nearly identical underlying UNCD layer. The composite film can be applied to any application currently utilizing a diamond or a similar hard film, including cutting tools, abrasive surfaces, electrochemistry, biomedical applications such as human implants or thermally conductive films and the like, requiring superior durability, chemical resistance and/or immunological inertness.

According to the present disclosure, a coated member is provided with a base material and a diamond layer located on the base material. When a ratio (SP3/SP2) obtainable from an SP3 peak derived from diamond crystals measurable by Raman spectroscopy and an SP2 peak derived from a graphite phase is referred to as an SP3 ratio, an SP3 ratio at a first measuring point with a thickness up to 1 m extending from an interface of the base material and the diamond layer toward the diamond layer is higher than an SP3 ratio at a second measuring point that is intermediate in a thickness direction of the diamond layer.

The crystal plane in the interior of the diamond substrate has a curvature higher than 0 km.sup.1 and equal to or lower than 1500 km.sup.1 by preparing a base substrate, forming a plurality of pillar-shaped diamonds formed of diamond single crystals on one side of the base substrate, causing diamond single crystals to grow from tips of each pillar-shaped diamond, coalescing each of the diamond single crystals grown from the tips of each pillar-shaped diamond to form a diamond substrate layer, separating the diamond substrate layer from the base substrate, and manufacturing the diamond substrate from the diamond substrate layer.

A method of fabricating a plurality of single crystal CVD diamonds, the method comprising: coating a carrier substrate with a layer of polycrystalline CVD diamond material; bonding a plurality of single crystal diamond substrates to the layer of polycrystalline CVD diamond material on the carrier substrate; growing single crystal CVD diamond material on the plurality of single crystal diamond substrates to form a plurality of single crystal CVD diamonds; and separating the plurality of single crystal CVD diamonds from the layer of polycrystalline CVD diamond material on the carrier substrate and any polycrystalline CVD diamond material which has grown between the plurality of single crystal CVD diamonds to yield a plurality of individual single crystal CVD diamonds.

A diamond coating includes a first diamond layer made of minute diamond particles and a second diamond layer made of coarse diamond particles: in a flank-face side diamond coating, a mean coat thickness d2 is not less than 3 m and not more than 25 m, a first diamond layer is formed on a surface side and a second diamond layer is formed on a tool base side: a rake-face side diamond coating is in a smaller range of 50 m or 1/10 of a tool diameter from a tip of a base cutting-edge part; in the rake-face side diamond coating, a mean coat thickness d1 is a smaller one in a range not less than 0 m and not more than 5.0 m or a range less than d2: and a boundary part between the first diamond layer and the second diamond layer.

Methods of depositing a nanocrystalline diamond film are described. The method may be used in the manufacture of integrated circuits. Methods include treating a substrate with a mild plasma to form a treated substrate surface, incubating the treated substrate with a carbon-rich weak plasma to nucleate diamond particles on the treated substrate surface, followed by treating the substrate with a strong plasma to form a nanocrystalline diamond film.

Methods for treating a thin film made from a conductive or semiconductive material may improve the crystalline quality thereof. Such methods may include: supplying a substrate including, on one of the faces thereof, a thin film of the material; and biased plasma treating the assembly formed by the substrate and the thin film at a given temperature and for a given time, so as to obtain a crystalline reorganization over a depth of the thin film, the biased plasma treatment including an electrical biasing of the thin film and an exposure of the film thus biased to a hydrogen plasma, the biased plasma treatment being implemented at a temperature that is below the melting points of the thin film and of the substrate.

Disclosed are a method of manufacturing a diamond electrode by a chemical vapor deposition (CVD) process, and a diamond electrode manufactured by the method. The method of manufacturing the diamond electrode includes: introducing a carbon source gas to form niobium carbide (NbC) on a niobium substrate, immediately before depositing an electrically conductive diamond layer on the substrate by a hot-filament chemical vapor deposition (HFCVD) process; and depositing electrically conductive diamond layers on the substrate by two or more separate processes. Accordingly, a pinhole present during deposition of the electrically conductive diamond layer is filled such that the contact between an electrolyte and the substrate in an electrolytic environment will be minimized so as to retard the corrosion of the substrate, thereby providing a diamond electrode having a long life span.

The crystal plane in the interior of the diamond substrate has a curvature higher than 0 km.sup.1 and equal to or lower than 1500 km.sup.1 by preparing a base substrate, forming a plurality of pillar-shaped diamonds formed of diamond single crystals on one side of the base substrate, causing diamond single crystals to grow from tips of each pillar-shaped diamond, coalescing each of the diamond single crystals grown from the tips of each pillar-shaped diamond to form a diamond substrate layer, separating the diamond substrate layer from the base substrate, and manufacturing the diamond substrate from the diamond substrate layer.

The crystal plane in the interior of the diamond substrate has a curvature higher than 0 km.sup.1 and equal to or lower than 1500 km.sup.1 by preparing a base substrate, forming a plurality of pillar-shaped diamonds formed of diamond single crystals on one side of the base substrate, causing diamond single crystals to grow from tips of each pillar-shaped diamond, coalescing each of the diamond single crystals grown from the tips of each pillar-shaped diamond to form a diamond substrate layer, separating the diamond substrate layer from the base substrate, and manufacturing the diamond substrate from the diamond substrate layer.