A method of fabricating semi-polar gallium nitride includes providing a silicon-on-insulator (SOI) substrate. The SOI substrate includes a substrate, a silicon oxide layer and a silicon substrate. The silicon substrate has (1,0,0) facets. The silicon oxide layer is disposed between the substrate and the silicon substrate. Later, a vapor etching process is performed to etch the (1,0,0) facets to form (1,1,1) facets. The vapor etching process is performed by disposing a nebulizer under the SOI substrate. The top surface of the silicon substrate faces the nebulizer. Later, the nebulizer turns etchant into mist to etch the (1,0,0) facets by the mist to form (1,1,1) facets. Finally, an epitaxial process is performed to grow a semi-polar gallium nitride layer on the (1,1,1) facets.

The present invention provides a metal nitride platform for semiconductor devices, including, a pre-defined array of catalyst sites, disposed on a substrate. Metal nitride islands with lateral to vertical size ratios of at least greater than one (1) are disposed on the array of catalyst sites, where the surfaces of the metal nitride islands are with reduced dislocation densities and side walls with bending of dislocations. The platform of metal nitride islands is further used to build electrically and optically-active devices. The present invention also provides a process for the preparation of a metal nitride platform, selectively, on the array of catalyst sites, in the presence of a reactive gas and precursors and under preferred reaction conditions, to grow metal nitride islands with lateral to vertical size ratios of at least greater than one (1).

The silicon carbide layer includes a second main surface opposite to a surface in contact with the silicon carbide single crystal substrate. The second main surface corresponds to a plane inclined relative to a {0001} plane in an off direction. The second main surface has a maximum diameter of not less than 100 mm. The second main surface has an outer circumferential region and a central region, the central region being surrounded by the outer circumferential region. The central region is provided with a first dislocation array of first half loops along a straight line perpendicular to the off direction. Each of the first half loops includes a pair of threading edge dislocations exposed at the second main surface. An area density of the first dislocation array at the central region is not more than 10/cm.sup.2.

There is provided a method for manufacturing a group III nitride substrate, including: preparing a plurality of seed crystal substrates formed into shapes that can be arranged with side surfaces opposed to each other; bonding the plurality of seed crystal substrates on a base material by an adhesive agent in an appearance that the seed crystal substrates are arranged with the side surfaces opposed to each other; growing a group III nitride crystals above main surfaces of the plurality of seed crystal substrates, so that crystals grown on each main surface are integrally combined each other; and obtaining a group III nitride substrate formed of the group III nitride crystal.

The present invention discloses single-walled carbon nanotubes horizontal arrays with ultra-high density and the preparation method. The method comprises the following steps: loading a catalyst on a single crystal growth substrate; after annealing, introducing hydrogen into a chemical vapor deposition system to conduct a reduction reaction of the catalyst; and maintaining the introduction of the hydrogen to conduct the orientated growth of a single-walled carbon nanotube. The density of the ultra-high density single-walled carbon nanotube horizontal array obtained by this method exceeds 130 tubes/micrometer, and an electrical performance test is performed on the prepared ultra-high density single-walled carbon nanotube horizontal array shows a high on-current density of 380 μA/μm, and the transconductance of 102.5 μS/μm.

The present invention provides a method for manufacturing a diamond substrate, including: a first step of preparing patterned diamond on a foundation surface, a second step of removing a foreign substance adhered on a wall of the patterned diamond prepared in the first step, and a third step of growing diamond from the patterned diamond prepared in the first step to form the diamond in a pattern gap of the patterned diamond prepared in the first step. There can be provided a method for manufacturing a diamond substrate with few dislocation defects, in which generation of abnormal growth particles are suppressed.

The present invention provides a method for manufacturing a diamond substrate, including: a first step of preparing patterned diamond on a foundation surface, a second step of growing diamond from the patterned diamond prepared in the first step to form the diamond in a pattern gap of the patterned diamond prepared in the first step, a third step of removing the patterned diamond prepared in the first step to form a patterned diamond composed of the diamond formed in the second step, and a fourth step of growing diamond from the patterned diamond formed in the third step to form the diamond in a pattern gap of the patterned diamond formed in the third step. There can be provided a method for manufacturing a diamond substrate which can sufficiently suppress dislocation defects, a high-quality diamond substrate, and a freestanding diamond substrate.

In a single-crystal diamond material, a concentration of non-substitutional nitrogen atoms is not more than 200 ppm, a concentration of substitutional nitrogen atoms is lower than the concentration of the non-substitutional nitrogen atoms, and the single-crystal diamond material has a crystal growth main surface having an off angle of not more than 20°. A perforated tool includes a single-crystal diamond die, wherein in the single-crystal diamond die, a concentration of non-substitutional nitrogen atoms is not more than 200 ppm, a concentration of substitutional nitrogen atoms is lower than the concentration of the non-substitutional nitrogen atoms, and the single-crystal diamond die has a low-index plane represented by a Miller index of not less than −5 and not more than 5 in an integer, a perpendicular line of the low-index plane having an off angle of not more than 20° relative to an orientation of a hole for wire drawing.

A method of manufacturing a diamond by a vapor phase synthesis method includes: preparing a substrate including a diamond seed crystal; forming a light absorbing layer lower in optical transparency than the substrate by performing ion implantation into the substrate, the light absorbing layer being formed at a predetermined depth from a main surface of the substrate; growing a diamond layer on the main surface of the substrate by the vapor phase synthesis method; and separating the diamond layer from the substrate by applying light from a main surface of at least one of the diamond layer and the substrate to allow the light absorbing layer to absorb the light and cause the light absorbing layer to be broken up.

Provided are a diamond composite body capable of shortening a separation time for separating a substrate and a diamond layer, the substrate, and a method for manufacturing a diamond, as well as a diamond obtained from the diamond composite body and a tool including the diamond. The diamond composite body includes a substrate including a diamond seed crystal and having grooves in a main surface, a diamond layer formed on the main surface of the substrate, and a non-diamond layer formed on a substrate side at a constant depth from an interface between the substrate and the diamond layer.