A film formation apparatus includes a stage, a heater, a mist supply source, a superheated vapor supply source, and a delivery device. The stage is configured to allow a substrate to be mounted thereon. The heater is configured to heat the substrate. The mist supply source is configured to supply mist of a solution that comprises solvent and a film material dissolved in the solvent. The superheated vapor supply source is configured to supply a superheated vapor of a same material as the solvent. The delivery device is configured to deliver the mist and the superheated vapor toward a surface of the substrate to grow a film containing the film material on the surface of the substrate.

A group III nitride single crystal substrate comprises: a first main face; and a first back face opposite to the first main face, wherein an absolute value of a radius of curvature of the first main face of the substrate is 10 m or more; an absolute value of a radius of curvature of a crystal lattice plane at a center of the first main face of the substrate is 10 m or more; and a 1/1000 intensity width of an X-ray rocking curve of a low-incidence-angle face at the center of the first main face of the substrate is 1200 arcsec or less.

A group III nitride single crystal substrate comprises: a first main face; and a first back face opposite to the first main face, wherein an absolute value of a radius of curvature of the first main face of the substrate is 10 m or more; an absolute value of a radius of curvature of a crystal lattice plane at a center of the first main face of the substrate is 10 m or more; and a 1/1000 intensity width of an X-ray rocking curve of a low-incidence-angle face at the center of the first main face of the substrate is 1200 arcsec or less.

An epitaxial structure includes a substrate, a nucleation layer on the substrate, a buffer layer on the nucleation layer, and a nitride layer on the buffer layer. The nucleation layer consists of regions in a thickness direction, wherein a chemical composition of the regions is Al.sub.(1-x)In.sub.xN, where 0≤x≤1. A maximum value of the x value in the plurality of regions is the same, a minimum value of the x value in the plurality of regions is the same, and an absolute value of a gradient slope of each of the regions is 0.1%/nm to 50%/nm. A thickness of the nucleation layer is less than a thickness of the buffer layer. A roughness of a surface of the nucleation layer in contact with the buffer layer is greater than a roughness of a surface of the buffer layer in contact with the nitride layer.

Methods for preparing epitaxial wafers are disclosed. The methods may involve control of the (i) a growth velocity, v, and/or (ii) an axial temperature gradient, G, during the growth of an ingot segment such that v/G is less than a critical v/G. An epitaxial layer is deposited on a substrate sliced from the silicon ingot.

A method of fabricating a plurality of single crystal CVD diamonds. The method includes mounting a plurality of single crystal diamond substrates on a first carrier substrate. The plurality of single crystal diamond substrates is subjected to a first CVD diamond growth process to form a plurality of single crystal CVD diamonds on the plurality of single crystal diamond substrates. The plurality of single crystal CVD diamonds are mounted in a recessed carrier substrate and subjected to a second CVD diamond growth process.

A method of fabricating a plurality of single crystal CVD diamonds. The method includes mounting a plurality of single crystal diamond substrates on a first carrier substrate. The plurality of single crystal diamond substrates is subjected to a first CVD diamond growth process to form a plurality of single crystal CVD diamonds on the plurality of single crystal diamond substrates. The plurality of single crystal CVD diamonds are mounted in a recessed carrier substrate and subjected to a second CVD diamond growth process.

The present application provides a method for manufacturing a monocrystalline silicon sheet, including: cutting a monocrystalline silicon rod along a radial or an axial direction of the monocrystalline silicon rod to obtain a monocrystalline silicon substrate; etching a porous silicon structure on a top surface and a bottom surface of the monocrystalline silicon substrate by wet etching; depositing a monocrystalline silicon thin layer on the porous silicon structure by chemical vapor deposition, so that a thickness of the monocrystalline silicon thin layer reaches a predetermined value; and striping the monocrystalline silicon thin layer from the porous silicon structure to obtain the monocrystalline silicon sheet. In the present application, the production capacity of directly manufacturing a single crystal silicon wafer by a chemical vapor deposition method can be improved, and a process for manufacturing a silicon wafer is combined with the process of a diffusion emitter conventionally belonging to cell manufacturing, so that a manufacturing cost of a solar monocrystalline silicon cell is significantly reduced.

A SiC single crystal is produced by impregnating a molten alloy of silicon and a metallic element M that increases carbon solubility into a SiC sintered body to form a SiC crucible, placing silicon and M in the crucible and heating the crucible to melt the silicon and M and form a Si—C solution, dissolving silicon and carbon in the solution from surfaces of the crucible in contact with the solution, contacting a SiC seed crystal with the top of the solution to grow a first SiC single crystal on the SiC seed crystal by a solution process, and bulk growing a second SiC single crystal on a face of the solution-grown first SiC single crystal by a sublimation or gas process. This method enables a low-dislocation, high-quality SiC single crystal to be produced by a vapor phase process.

Provided is a method for manufacturing a semiconductor silicon wafer capable of inhibiting P-aggregation defects (Si-P defects) and SF in an epitaxial layer. The method includes a step of forming a silicon oxide film with a thickness of at least 300 nm or thicker only on the backside of the silicon wafer substrate by the CVD method at a temperature of 500° C. or lower after the step of forming the silicon oxide film, a step of heat treatment where the substrate is kept in an oxidizing atmosphere at a constant temperature of 1100° C. or higher and 1250° C. or lower for 30 minutes or longer and 120 minutes or shorter after the heat treatment, a step of removing surface oxide film formed on the front surface of the substrate, and a step of depositing a silicon monocrystalline epitaxial layer on the substrate after the step of removing the surface oxide film.