A method of acquiring a sample for evaluation of a SiC single crystal, comprising: a step of cutting a SiC ingot in a radial direction at a thickness position, which is located in a range from a curved surface which forms a distal end surface in a crystal growth direction to a seed crystal, to obtain a head member which includes the curved surface, wherein the SiC ingot used in the step is a SiC ingot in which SiC thereof is crystal-grown from a seed crystal along a c axis direction; and a step of polishing a silicon surface of the head member to obtain a sample for evaluation.

A method for growing crystals using PVT or PVD or CVD, includes: providing: a chamber for crystal growth, a crucible in the chamber including at least one deposition section with a seed crystal and a base material for crystal growth, at least one temperature monitoring device, a gas supply device and at least one fluid inlet and outlet, and a pressure monitoring device; evacuating the chamber using a pumping device; flushing the chamber with an inert gas; heating the chamber to a growth temperature of 2000 to 2400° C. using at least one heating device; decreasing pressure to 0.1 to 100 mbar; supplying a dopant, (during a growth process); regulating process parameters in the growth process; increasing chamber pressure at the growth process end; cooling down the chamber; wherein the heating of the chamber from an ambient temperature to the growth temperature occurs within 10 to 10000 minutes.

A method of forming a film comprises growing, using a deposition system, at least a portion of the film and analyzing, using a RHEED instrument, the at least a portion of the film. Using a computer, data is acquired from the RHEED instrument that is indicative of a stoichiometry of the at least a portion of the film. Using the computer, adjustments to one or more process parameters of the deposition system are calculated to control stoichiometry of the film during subsequent deposition. Using the computer, instructions are transmitted to the deposition system to execute the adjustments of the one or more process parameters. Using the deposition system, the one or more process parameters are adjusted.

Methods for depositing films using crystals or powders as a source material are provided. The films can have a thickness of at least 100 nanometers and can be inorganic (e.g., inorganic perovskite) films, and the source material can be the same composition and/or stoichiometry as the deposited film. The deposition process can be a single-step thermal process using a close space sublimation (CSS) process.

Embodiments described herein include a method for depositing a material layer on a substrate while controlling a bow of the substrate and a surface roughness of the material layer. A bias applied to the substrate while the material layer is deposited is adjusted to control the bow of the substrate. A bombardment process is performed on the material layer to improve the surface roughness of the material layer. The bias and bombardment process improve a uniformity of the material layer and reduce an occurrence of the material layer cracking due to the bow of the substrate.

In various embodiments, single-crystal aluminum nitride boules and substrates having high transparency to ultraviolet light and low defect density are formed. The single-crystal aluminum nitride may function as a platform for the fabrication of light-emitting devices such as light-emitting diodes and lasers.

A SiC ingot includes: a main body including a first cross-sectional plane of the main body and a second cross-sectional plane of the main body facing the first cross-sectional plane; and a protrusion disposed on the second cross-sectional plane and including a convex surface from the second cross-sectional plane of the main body, wherein a first end point disposed at one end of the second cross sectional plane, a second end point disposed at another end of the second cross sectional plane, and a peak point disposed on the convex surface are disposed on a third cross-sectional plane of the main body perpendicular to the first cross-sectional plane, and wherein a radius of curvature of an arc corresponding to a line of intersection between the third cross-sectional plane and the convex surface satisfies Equation 1 below:

3D≤r≤37D  [Equation 1]

where r is the radius of curvature of the arc corresponding to the line of intersection between the third cross-sectional plane and the convex surface, and D is a length of a line of intersection between the first cross-sectional plane and the third cross-sectional plane.

A SiC ingot includes a core portion; and a surface layer that is formed on a plane of the core portion in a growing direction, and a coefficient of linear thermal expansion of the surface layer is smaller than a coefficient of linear thermal expansion of the core portion.

An adhesive layer of seed crystal includes a graphitized adhesive layer, wherein the graphitized adhesive layer is prepared by heat-treating a pre-carbonized adhesive layer, and wherein the adhesive layer has Vr value of 28%/mm.sup.3 or more, and the Vr value is represented by Equation 1 below: $\begin{array}{cc}\mathrm{Vr}=\left\{\frac{\mathrm{Sq}}{\left(V1-V2\right)}\right\}\times 10^3& \left[\mathrm{Equation}1\right]\end{array}$ where Sg (%) is represented by Equation 2 below, V1 is a volume (mm.sup.3) of the pre-carbonized adhesive layer, and V2 is a volume (mm.sup.3) of the graphitized adhesive layer, $\begin{array}{c}\mathrm{Sg}=\left\{1-\left(\frac{A2}{A1}\right)\right\}\times 1\end{array}$

A silicon carbide ingot manufacturing method and a silicon carbide ingot manufacturing system are provided. The silicon carbide ingot manufacturing method and the silicon carbide ingot manufacturing system may change a temperature gradient depending on the growth of an ingot by implementing a guide which has a tilted angle to an external direction from the interior of a reactor, in an operation to grow an ingot during a silicon carbide ingot manufacturing process.