A method for manufacturing a compound semiconductor substrate that can achieve thinning of SiC film, wherein the method includes forming a SiC film on one principal surface side of a Si substrate and forming a recessed part in which a bottom surface is Si in a central part of another principal surface of the Si substrate.

A group III nitride crystal, wherein the group III nitride crystal is doped with an N-type dopant and a germanium element, the concentration of the N-type dopant is 1×10.sup.19 cm.sup.−3 or more, and the concentration of the germanium element is nine times or more higher than the concentration of the N-type dopant.

In a method of forming a diamond film, substrate, or window, a substrate is provided and the diamond film, substrate, or window is CVD grown on a surface of the substrate. The grown diamond film, substrate, or window has a thickness between 150-999 microns and an aspect ratio≥100, wherein the aspect ratio is a ratio of a largest dimension of the diamond film, substrate or window divided by a thickness of the diamond film. The substrate can optionally be removed or separated from the grown diamond film, substrate, or window.

In a method of forming a diamond film, substrate, or window, a substrate is provided and the diamond film, substrate, or window is CVD grown on a surface of the substrate. The grown diamond film, substrate, or window has a thickness between 150-999 microns and an aspect ratio≥100, wherein the aspect ratio is a ratio of a largest dimension of the diamond film, substrate or window divided by a thickness of the diamond film. The substrate can optionally be removed or separated from the grown diamond film, substrate, or window.

An ultra-fine nanocrystalline diamond precision cutting tool and a manufacturing method therefor. A diamond cutter is made of a thick self-supporting film of ultra-fine nanocrystalline diamond, the thick film having a thickness of 100-3000 microns, where 1 nanometer≤diamond grain size≤20 nanometers. In the manufacturing method, the growth of ultra-fine nanocrystalline diamond on a silicon substrate is accomplished by means of two steps of direct current hot cathode glow discharge chemical vapor deposition and hot filament chemical vapor deposition, then the silicon substrate is separated from the diamond to obtain a thick self-supporting film of ultra-fine nanocrystalline diamond, the thick self-supporting film of ultra-fine nanocrystalline diamond is laser cut and then welded to a cutter body, and then by means of edging, rough grinding and fine grinding, an ultra-fine nanocrystalline diamond precision cutting tool is obtained.

The invention relates to a method for producing at least one solid layer and comprises at least the steps of: providing a carrier substrate (4) having a sacrificial layer (8) arranged thereon or arranging a sacrificial layer (8) on the provided carrier substrate (4), producing a useful layer (6) by way of chemical or physical gas phase deposition on the sacrificial layer (8) to form a multi-layer arrangement (2), removing the useful layer (6) as a result of a material weakening produced between the useful layer (6) and the carrier substrate (4), said material weakening being brought about by modifications (12) to the sacrificial layer (8) which were produced means of laser beams (10).

The invention relates to a method for producing at least one solid layer and comprises at least the steps of: providing a carrier substrate (4) having a sacrificial layer (8) arranged thereon or arranging a sacrificial layer (8) on the provided carrier substrate (4), producing a useful layer (6) by way of chemical or physical gas phase deposition on the sacrificial layer (8) to form a multi-layer arrangement (2), removing the useful layer (6) as a result of a material weakening produced between the useful layer (6) and the carrier substrate (4), said material weakening being brought about by modifications (12) to the sacrificial layer (8) which were produced means of laser beams (10).

Provided herein are Si-based materials, methods of making the Si-based materials, and methods for using the Si-based materials. In embodiments, a silicon-based material comprises an aggregate of particles, the particles comprising an ordered array of nanostructures, the nanostructures comprising amorphous silicon, wherein at least some pairs of adjacent nanostructures are connected by one or more bridges comprising amorphous silicon, the one or more bridges extending from the surface of one nanostructure of the pair to the surface of the other nanostructure in the pair.

Provided herein are Si-based materials, methods of making the Si-based materials, and methods for using the Si-based materials. In embodiments, a silicon-based material comprises an aggregate of particles, the particles comprising an ordered array of nanostructures, the nanostructures comprising amorphous silicon, wherein at least some pairs of adjacent nanostructures are connected by one or more bridges comprising amorphous silicon, the one or more bridges extending from the surface of one nanostructure of the pair to the surface of the other nanostructure in the pair.

In a method of forming a diamond film, substrate, or window, a substrate is provided and the diamond film, substrate, or window is CVD grown on a surface of the substrate. The grown diamond film, substrate, or window has a thickness between 150-999 microns and an aspect ratio≥100, wherein the aspect ratio is a ratio of a largest dimension of the diamond film, substrate or window divided by a thickness of the diamond film. The substrate can optionally be removed or separated from the grown diamond film, substrate, or window.