A wafer having relaxation moduli different by 450 GPa or less, as determined by dynamic mechanical analysis, when loaded to 1 N and 18 N with a loading rate of 0.1 N/min at a temperature of 25° C.

A wafer having relaxation moduli different by 450 GPa or less, as determined by dynamic mechanical analysis, when loaded to 1 N and 18 N with a loading rate of 0.1 N/min at a temperature of 25° C.

An object of the present invention is to provide a novel SiC single crystal with reduced internal stress while suppressing SiC sublimation. In order to solve the above problems, the present invention provides a method for producing SiC single crystals, including a stress reduction step of heating a SiC single crystal at 1800° C. or higher in an atmosphere containing Si and C elements to reduce internal stress in the SiC single crystal. With this configuration, the present invention can provide a novel SiC single crystal with reduced internal stress while suppressing SiC sublimation.

A silicon carbide single crystal manufacturing apparatus includes a crucible constituted by a crucible body and a crucible lid and a base having a crucible lid side surface supported by the lower surface of the crucible lid, and a seed crystal mounting surface on which the seed crystal is mounted and which is a surface on the opposite side of the crucible lid side surface, wherein the base is made of graphite material, the area of the seed crystal mounting surface is larger than the area of the crucible lid side surface, and the base has at least of a portion in which the cross-sectional area orthogonal to the vertical direction connecting the crucible lid side surface and the seed crystal mounting surface is gradually reduced, and a portion that is getting smaller gradually, from the surface of the seed crystal mounting surface toward the crucible lid side surface.

A Ga.sub.2O.sub.3-based semiconductor device includes a Ga.sub.2O.sub.3-based crystal layer including a donor, and an N-doped region formed in at least a part of the Ga.sub.2O.sub.3-based crystal layer.

A system for simultaneously manufacturing more than one single crystal of a semiconductor material by physical vapor transport (PVT) includes a plurality of reactors and a common vacuum channel connecting at least a pair of reactors of the plurality of reactors. Each reactor has an inner chamber adapted to accommodate a PVT growth structure for growth of a single semiconductor crystal. The common vacuum channel is connectable to a vacuum pump system for creating and/or controlling a common gas phase condition in the inner chambers of the pair of reactors.

Various embodiments of the present technology enable growth of a-axis oriented barium titanate (BTO) films by inserting a relaxed strain control layer having a larger lattice constant than the c-axis of BTO and a similar thermal expansion mismatch. As a result, in-plane tensile stress causes BTO to grow with its ferroelectric polarization in-plane. Some embodiments allow for BTO films to immediately be grown on silicon with a-axis orientation, and without the need to create thick layers for relaxation. Using various embodiments of the present technology, the BTO can be grown in-plane with minimal dislocation density that is confined to the interface region.

Embodiments of the present disclosure generally relate to a substrate support having a two-part surface coating which reduces defect formation and back side metal contamination during substrate processing. A support body includes a body having an upper surface and a two-part coating disposed over the upper surface of the body. The two-part coating includes a first coating layer extending a first radial distance from a center of the body. The first coating layer includes at least one of a metal-containing material or alloy. The two-part coating includes a second coating layer disposed over the first coating layer. The second coating layer extends a second radial distance from the center of the body. The first radial distance is greater than the second radial distance. The second coating layer is non-metal.

A surface acoustic wave device includes a piezoelectric single crystal substrate and an electrode. The piezoelectric single crystal substrate is made of LiTaO.sub.3 or LiNbO.sub.3. The electrode includes a titanium film formed on the piezoelectric single crystal substrate and an aluminum film or a film containing aluminum as a main component. The aluminum film or the film is formed on the titanium film. The aluminum film or the film containing aluminum as the main component is a twin crystal film or a single crystal film, the aluminum film or the film has a (111) plane that is non-parallel to a surface of the piezoelectric single crystal substrate with an angle θ, and the aluminum film or the film has a [−1, 1, 0] direction parallel to an X-direction of a crystallographic axis of the piezoelectric single crystal substrate.

Silicon carbide (SiC) crystalline materials and related methods are disclosed that provide SiC crystalline materials with reduced optical absorption. In certain aspects, SiC crystalline materials with reduced absorption coefficients for wavelengths of light within the visible spectrum are disclosed. Various peaks in absorption over a wavelength spectrum may be reduced in SiC crystalline materials to improve overall absorption coefficient uniformity across the visible spectrum. By providing such improvements in absorption coefficients for SiC crystalline materials, reduced reflection and transmission losses of light in corresponding devices may be realized. Related methods are disclosed that include various combinations of crystalline growth, with and without various post-growth thermal conditioning steps.