The disclosure provides a silicon carbide seed crystal and a method of manufacturing a silicon carbide ingot. The silicon carbide seed crystal has a silicon surface and a carbon surface opposite to the silicon surface. A difference D between a basal plane dislocation density BPD1 of the silicon surface and a basal plane dislocation density BPD2 of the carbon surface satisfies the following formula (1), a local thickness variation (LTV) of the silicon carbide seed crystal is 2.5 μm or less, and a stacking fault (SF) density of the silicon carbide seed crystal is 10 EA/cm.sup.2 or less:

D=(BPD1−BPD2)/BPD1≤25%  (1).

A method for manufacturing epitaxial films with multiple stress states, comprising steps of: providing a first single crystal substrate, and forming a sacrificial layer and a first epitaxial film on the first single crystal substrate, wherein the first epitaxial film is made of a first material;

removing the sacrificial layer to separate the first epitaxial film from the first single crystal substrate; transferring the first epitaxial film to a second single crystal substrate, wherein the second single crystal substrate is made of a second material, a partial surface of the second single crystal substrate being overlapped by the first epitaxial film; applying epitaxies onto the first epitaxial film and the second single crystal substrate to form a second epitaxial film on the first epitaxial film and the second single crystal substrate.

An object is to provide a nonpolar or semipolar GaN substrate having improved size and crystal quality. A self-standing GaN substrate has an angle between the normal of the principal surface and an m-axis of 0 degrees or more and 20 degrees or less, wherein: the size of the projected image in a c-axis direction when the principal surface is vertically projected on an M-plane is 10 mm or more; and when an a-axis length is measured on an intersection line between the principal surface and an A-plane, a low distortion section with a section length of 6 mm or more and with an a-axis length variation within the section of 10.0×10.sup.−5 Å or less is observed.

Methods and systems of heating a substrate in a vacuum deposition process include a resistive heater having a resistive heating element. Radiative heat emitted from the resistive heating element has a wavelength in a mid-infrared band from 5 μm to 40 μm that corresponds to a phonon absorption band of the substrate. The substrate comprises a wide bandgap semiconducting material and has an uncoated surface and a deposition surface opposite the uncoated surface. The resistive heater and the substrate are positioned in a vacuum deposition chamber. The uncoated surface of the substrate is spaced apart from and faces the resistive heater. The uncoated surface of the substrate is directly heated by absorbing the radiative heat.

The present invention relates to a silicon carbide (SiC) substrate with improved mechanical and electrical characteristics. Furthermore, the invention relates to a method for producing a bulk SiC crystal in a physical vapor transport growth system. The silicon carbide substrate comprises an inner region (102) which constitutes at least 30% of a total surface area of said substrate (100), a ring shaped peripheral region (104) radially surrounding the inner region (102), wherein a mean concentration of a dopant in the inner region (102) differs by at least 1-10.sup.18 cm-.sup.3 from the mean concentration of this dopant in the peripheral region (104).

An object of the present invention is to provide a novel technology capable of achieving high-quality SiC seed crystal, SiC ingot, SiC wafer and SiC wafer with an epitaxial film. The present invention, which solves the above object, is a method for producing a SiC seed crystal for growth of a SiC ingot, the method including a heat treatment step of heat-treating a SiC single crystal in an atmosphere containing Si element and C element. As described above, by heat-treating the SiC single crystal in an atmosphere containing the Si element and the C element, it is possible to produce a high-quality SiC seed crystal in which strain and crystal defects are suppressed.

A method for method for manufacturing a rutile titanium dioxide layer according to the inventive concept includes forming a sacrificial layer on a substrate, and depositing a titanium dioxide (TiO.sub.2) material on the sacrificial layer. The sacrificial layer includes a metal oxide of a rutile phase. An amount of oxygen vacancy of the sacrificial layer after depositing the titanium dioxide material is greater than an amount of oxygen vacancy of the sacrificial layer before depositing the titanium dioxide material. The metal oxide includes a metal different from titanium (Ti).

A SiC single crystal composite includes: a central portion positioned at a center in plan view; and an outer circumferential portion surrounding an outer circumference of the central portion, in which crystal planes of the central portion and the outer circumferential portion are inclined to each other or different from each other, a boundary is present between the central portion and the outer circumferential portion, and a direction of a crystal constituting the central portion and a direction of a crystal constituting the outer circumferential portion are different from each other via the boundary.

By widening a terrace on a crystal surface on a bottom face of a recess by step flow caused by heating, a flat face is formed on the bottom face of the recess, a two-dimensional material layer made of a two-dimensional material is formed on the formed flat face, and then a device made of the two-dimensional material layer is produced.

A method of fabricating a semiconductor device includes providing a substrate, implementing a growth procedure to form a semiconductor layer supported by the substrate, performing an anneal of the semiconductor layer, the anneal being conducted at a higher temperature than the growth procedure, and repeating the growth procedure and the anneal. The anneal is conducted at or above a decomposition temperature for the semiconductor layer.