A silicon carbide ingot producing method is provided. The method produces a silicon carbide ingot in which an internal space of a reactor is depressurized and heated to create a predetermined difference in temperature between upper and lower portions of the internal space. The method produces a silicon carbide ingot in which a plane of a seed crystal corresponding to the rear surface of the silicon carbide ingot is lost minimally. Additionally, the method produces a silicon carbide ingot with few defects and good crystal quality.

A method for manufacturing an epitaxial substrate includes the steps of: epitaxially growing a group III nitride semiconductor layer on a substrate; removing the substrate from a growth furnace; irradiating a surface of the group III nitride semiconductor layer with ultraviolet light while exposing the surface to an atmosphere containing oxygen; and measuring a sheet resistance value of the group III nitride semiconductor layer.

A gallium arsenide single crystal substrate having a main surface, in which a ratio of the number of As atoms existing as diarsenic trioxide to the number of As atoms existing as diarsenic pentoxide is greater than or equal to 2 when the main surface is measured by X-ray photoelectron spectroscopy, in which an X-ray having energy of 150 eV is used and a take-off angle of a photoelectron is set to 5°. Arithmetic average roughness (Ra) of the main surface is less than or equal to 0.3 nm.

A method for manufacturing a silicon single-crystal substrate having a carbon diffusion layer on a surface, proximity gettering ability, and high strength near the surface, and hardly generating dislocation or extending dislocation, includes: a step of adhering carbon on a surface of a silicon single-crystal substrate by an RTA treatment of the silicon single-crystal substrate in a carbon-containing gas atmosphere; a step of forming a 3C-SiC single-crystal film on the surface of the silicon single-crystal substrate by reacting the carbon and the silicon single-crystal substrate; a step of oxidizing the 3C-SiC single-crystal film to be an oxide film and diffusing carbon inward the silicon single-crystal substrate by an RTA treatment of the silicon single-crystal substrate on which the 3C-SiC single-crystal film is formed, the RTA treatment being performed in an oxidative atmosphere; and a step of removing the oxide film.

Reduced and low work function materials capable of optimizing electron emission performance in a range of vacuum and nanoscale electronic devices and processes and a method for reducing work function and producing reduced and low work function materials are described. The reduced and low work function materials advantageously may be made from single crystal materials, preferably metals, and from amorphous materials with optimal thicknesses for the materials. A surface geometry is created that may significantly reduce work function and produce a reduced or low work function for the material. It is anticipated that low and ultra-low work function materials may be produced by the present invention and that these materials will have particular utility in the optimization of electron emissions in a wide range of vacuum microelectronics and other nanoscale electronics and processes.

Nano-wire growth processes, nano-wires, and articles having nano-wires are disclosed. The nano-wire growth process includes trapping growth-inducing particles on a substrate, positioning the substrate within a chamber, closing the chamber, applying a vacuum to the chamber, introducing a precursor gas to the chamber, and thermally decomposing the precursor gas. The thermally decomposing of the precursor gas grows nano-wires from the growth-inducing particles. The nano-wires and the articles having the nano-wires are produced by the nano-wire growth process.

There are provided a setting process configured to set in a chamber an aluminum nitride substrate in which a semiconductor layer is formed on a first principal plane, and an oxide film forming process configured to heat an inside of the chamber with a water molecule (H.sub.2O) being introduced in the chamber and to form an oxide film including an amorphous oxide film and/or a crystalline oxide film on a second principal plane located on an opposite side to the first principal plane of the aluminum nitride substrate.

A device includes a semiconductor substrate containing gallium nitride and having a crystal face inclined from 0.05° to 15° inclusive with respect to the c-plane. The semiconductor substrate includes an irregular portion on the crystal face, and the contact angle of pure water having a specific resistance of 18 MΩ.Math.cm or more on the surface of the irregular portion is 10° or less.

A biomedical implant (16, 18) is formed from magnesium (Mg) single crystal (10). The biomedical implant (16, 18) may be biodegradable. The biomedical implant (16, 18) may be post treated to control the mechanical properties and/or corrosion rate thereof said Mg single crystal (10) without changing the chemical composition thereof. A method of making a Mg single crystal (10) for biomedical applications includes filling a single crucible (12) with more than one chamber with polycrystalline Mg, melting at least a portion of said polycrystalline Mg, and forming more than one Mg single crystal (10) using directional solidification.

A method of forming an oxide film is provided. The method may include: supplying mist of a solution including a material of the oxide film dissolved therein to a surface of a substrate together with a carrier gas having an oxygen concentration equal to or less than 21 vol % so as to epitaxially grow the oxide film on the surface of the substrate; and bringing the oxide film into contact with a fluid comprising oxygen atoms after the epitaxial growth of the oxide film.