A composite nitride-based film structure includes a bulk single crystal, a plurality of nitride microcrystals, and an amorphous nitride thin film. The plurality of nitride microcrystals is provided on the bulk single crystal, and has a specific orientation relationship with a crystal structure of the bulk single crystal. The nitride thin film is provided on the bulk single crystal, surrounds the nitride microcrystal, and covers a surface of the bulk single crystal.

A process of preparing a wafer having a diameter of two inches or more, at least a surface of the wafer being formed from a group III nitride crystal, including preparing an alkaline or acidic etching liquid containing a peroxodisulfate ion as an oxidizing agent that accepts an electron, accommodating the wafer such that the surface of the wafer is immersed in the etching liquid such that the surface of the wafer is parallel with a surface of the etching liquid; and radiating light from the surface side of the etching liquid onto the surface of the wafer without agitating the etching liquid. First and second etching areas disposed at an interval from each other are defined on the surface of the wafer. In the process of radiating the light onto the surface of the wafer, the light is radiated perpendicularly onto surfaces of the first and second etching areas.

Processes for synthesizing the hexagonal polymorph of boron nitride (h-BN) produce h-BN of a grade that is highly suitable for ultraviolet (UV) field-emission lights and other UV applications.

A substrate processing method is described for forming a titanium nitride material that may be used for superconducting metallization or work function adjustment applications. The substrate processing method includes depositing by vapor phase deposition at least one monolayer of a first titanium nitride film on a substrate, and treating the first titanium nitride film with plasma excited hydrogen-containing gas, where the first titanium nitride film is polycrystalline and the treating increases the (200) crystallographic texture of the first titanium nitride film. The method further includes depositing by vapor phase deposition at least one monolayer of a second titanium nitride film on the treated at least one monolayer of the first titanium nitride film, and treating the at least one monolayer of the second titanium nitride film with plasma excited hydrogen-containing gas.

There is provided a nitride semiconductor substrate having a diameter of 2 inches or more and having a main surface whose closest low index crystal plane is a (0001) plane, wherein X-ray locking curve measurement for (0002) plane diffraction, which is performed to the main surface by irradiating with (Cu) Kα1 X-rays through a two-crystal monochromator of Ge (220) plane and a slit, reveals that full width at half maximum FWHMb is 32 arcsec or less, and FWHMa−FWHMb obtained by subtracting FWHMb from FWHMa is 30% or less of FWHMa, wherein FWHMa is full width at half maximum of the (0002) plane diffraction when a slit width in ω direction is 1 mm, and FWHMb is full width at half maximum of the (0002) plane diffraction when a slit width in ω direction is 0.1 mm.

There is provided a nitride semiconductor substrate having a diameter of 2 inches or more and having a main surface whose closest low index crystal plane is a (0001) plane, wherein X-ray locking curve measurement for (0002) plane diffraction, which is performed to the main surface by irradiating with (Cu) Kα1 X-rays through a two-crystal monochromator of Ge (220) plane and a slit, reveals that full width at half maximum FWHMb is 32 arcsec or less, and FWHMa−FWHMb obtained by subtracting FWHMb from FWHMa is 30% or less of FWHMa, wherein FWHMa is full width at half maximum of the (0002) plane diffraction when a slit width in ω direction is 1 mm, and FWHMb is full width at half maximum of the (0002) plane diffraction when a slit width in ω direction is 0.1 mm.

The embodiments of the present disclosure disclose a method and an apparatus for crystal growth. The method for crystal growth may include: placing a seed crystal and a target source material in a growth chamber of an apparatus for crystal growth; executing a growth of a crystal based on the seed crystal and the target source material according to physical vapor transport; determining whether a preset condition is satisfied during the crystal growth process; and in response to determining that the preset condition is satisfied, replacing a sublimated target source material with a candidate source material. In the present disclosure, by replacing the sublimated target source material with the candidate source material, a crystal with large-size and high-quality can be grown.

The embodiments of the present disclosure disclose a method and an apparatus for crystal growth. The method for crystal growth may include: placing a seed crystal and a target source material in a growth chamber of an apparatus for crystal growth; executing a growth of a crystal based on the seed crystal and the target source material according to physical vapor transport; determining whether a preset condition is satisfied during the crystal growth process; and in response to determining that the preset condition is satisfied, replacing a sublimated target source material with a candidate source material. In the present disclosure, by replacing the sublimated target source material with the candidate source material, a crystal with large-size and high-quality can be grown.

Provided is a technique for manufacturing a nitride semiconductor substrate with which it is possible to manufacture a nitride semiconductor substrate having sufficiently reduced dislocation density with a large area even if manufactured on an inexpensive substrate made of sapphire, etc. A nitride semiconductor substrate in which a nitride semiconductor layer formed on a substrate is formed by laminating an undoped nitride layer and a rare earth element-added nitride layer to which a rare earth element is added as a doping material, and the dislocation density is of the order of 106 cm−2 or less. A method for manufacturing a nitride semiconductor substrate in which a step for growing GaN, InN, AlN, or a mixed crystal of two or more thereof on a substrate to form an undoped nitride layer, and a step for forming a rare earth element-added nitride layer to which a rare earth element is added so as to be substituted for Ga, In, or Al are performed via a series of formation steps using an organic metal vapor epitaxial technique at a temperature of 900 to 1200° C. without extraction from a reaction vessel.

Provided is a technique for manufacturing a nitride semiconductor substrate with which it is possible to manufacture a nitride semiconductor substrate having sufficiently reduced dislocation density with a large area even if manufactured on an inexpensive substrate made of sapphire, etc. A nitride semiconductor substrate in which a nitride semiconductor layer formed on a substrate is formed by laminating an undoped nitride layer and a rare earth element-added nitride layer to which a rare earth element is added as a doping material, and the dislocation density is of the order of 106 cm−2 or less. A method for manufacturing a nitride semiconductor substrate in which a step for growing GaN, InN, AlN, or a mixed crystal of two or more thereof on a substrate to form an undoped nitride layer, and a step for forming a rare earth element-added nitride layer to which a rare earth element is added so as to be substituted for Ga, In, or Al are performed via a series of formation steps using an organic metal vapor epitaxial technique at a temperature of 900 to 1200° C. without extraction from a reaction vessel.