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 SiC epitaxial wafer includes a SiC substrate and an epitaxial layer laminated on the SiC substrate, wherein the epitaxial layer comprises a first layer, a second layer and a third layer in order from the SiC substrate side, the nitrogen concentration of the SiC substrate is 6.0×10.sup.18 cm.sup.−3 or more and 1.5×10.sup.19 cm.sup.−3 or less, the nitrogen concentration of the first layer is 1.0×10.sup.17 cm.sup.−3 or more and 1.5×10.sup.18 cm.sup.−3 or less, the nitrogen concentration of the second layer is 1.0×10.sup.18 cm.sup.−3 or more and 5.0×10.sup.18 cm.sup.−3 or less, and the nitrogen concentration of the third layer is 5.0×10.sup.13 cm.sup.−3 or more and 1.0×10.sup.17 cm.sup.−3 or less.

The present disclosure relates to the technical field of semiconductors. Disclosed is a multi-layer semiconductor material structure and a preparation method thereof, solving the problems of the existing semiconductor materials that have poor heat dissipation, high cost, and cannot be mass-produced. The multi-layer semiconductor material structure includes a highly thermally conductive support substrate and a crystallized device function layer, where the device function layer is provided on the highly thermally conductive support substrate, and has a single-crystal surface layer.

A semiconductor device includes a channel layer configured to include a first nitride semiconductor containing gallium (Ga) and a first crystal dislocation density, and a barrier layer provided over a first surface side of the channel layer, and configured to include a second nitride semiconductor containing aluminum (Al) and a second crystal dislocation density, wherein the second crystal dislocation density is larger than the first crystal dislocation density.

Wafers including a diamond layer and a semiconductor layer having III-Nitride compounds and methods for fabricating the wafers are provided. A nucleation layer, at least one semiconductor layer having III-Nitride compound and a protection layer are formed on a silicon substrate. Then, a silicon carrier wafer is glass bonded to the protection layer. Subsequently the silicon substrate, nucleation layer and a portion of the semiconductor layer are removed. Then, an intermediate layer, a seed layer and a first diamond layer are sequentially deposited on the III-Nitride layer. Next, the silicon carrier wafer and the protection layer are removed. Then, a silicon substrate wafer that includes a protection layer, silicon substrate and a diamond layer is prepared and glass bonded to the first diamond layer.

According to the present invention, there is provided a SiC epitaxial wafer including: a 4H-SiC single crystal substrate which has a surface with an off angle with respect to a c-plane as a main surface and a bevel part on a peripheral part; and a SiC epitaxial layer having a film thickness of 20 μm or more, which is formed on the 4H-SiC single crystal substrate, in which a density of an interface dislocation extending from an outer peripheral edge of the SiC epitaxial layer is 10 lines/cm or less.

A Group III-Nitride quantum well laser including a distributed Bragg reflector (DBR). In some embodiments, the DBR includes Scandium. In some embodiments, the DBR includes Al.sub.1-xSc.sub.xN, which may have 0<x≤0.45.

An embodiment semiconductor module includes a substrate, a heterogeneous thin film including a first semiconductor layer disposed on a first region of the substrate and a second semiconductor layer disposed on a second region of the substrate, a first semiconductor device disposed on the first semiconductor layer of the heterogeneous thin film, and a second semiconductor device disposed on the second semiconductor layer of the heterogeneous thin film, wherein one of the first semiconductor layer or the second semiconductor layer comprises gallium oxide (Ga.sub.2O.sub.3) and the other includes silicon (Si).

The present invention relates to a method for manufacturing a diamond substrate, and more particularly, to a method of growing diamond after forming a structure of an air gap having a crystal correlation with a lower substrate by heat treatment of a photoresist pattern and an air gap forming film material on a substrate such as sapphire (Al.sub.2O.sub.3). Through such a method, a process is simplified and the cost is lowered when large-area/large-diameter single crystal diamond is heterogeneously grown, stress due to differences in a lattice constant and a coefficient of thermal expansion between the heterogeneous substrate and diamond is relieved, and an occurrence of defects or cracks is reduced even when a temperature drops, such that a high-quality single crystal diamond substrate may be manufactured and the diamond substrate may be easily self-separated from the heterogeneous substrate.

A method of plasma etching a compound semiconductor substrate forms a feature. A first plasma etch step anisotropically etches the substrate through an opening to produce a partially formed feature having an opening and a bottom surface with a peripheral region. A second plasma etch step removes a region of the mask adjacent to the opening of the partially formed feature thereby causing rounding of the edges of the substrate at the opening of the partially formed feature. A third plasma etch step anisotropically etches the bottom surface of the partially formed feature through the opening of the mask while depositing a passivation material onto the mask and the opening of the partially formed feature to reduce a dimension of the opening of the partially formed feature. A plasma etch apparatus can be used to perform the method.