A process for epitaxying GaSe on a [111]-oriented silicon substrate, includes a step of selecting a [111]-oriented silicon substrate resulting from cutting a silicon bar in a miscut direction which is one of the three [11-2] crystallographic directions, the miscut angle (α) being smaller than or equal to 0.1°, the obtained surface of the substrate forming a vicinal surface exhibiting a plurality of terraces and at least one step between two terraces; a passivation step consisting of depositing an atomic bilayer of gallium and of selenium on the vicinal surface of the silicon substrate so as to form a passivated vicinal surface made of silicon-gallium-selenium (Si—Ga—Se), said passivated vicinal surface exhibiting a plurality of passivated terraces and at least one passivated step between two passivated terraces; a step of forming a layer of two-dimensional GaSe by epitaxy on the passivated surface, said formation step comprising a step of nucleation from each passivated step and a step of lateral growth on the passivated terraces from the nuclei obtained in the nucleation step. A structure obtained by means of the epitaxying process is also provided.

Disclosed herein is a method for 2D epitaxial growth comprising: forming a single crystalline h-BN template; forming a plurality of nuclei by depositing a heterogeneous precursor on the h-BN template; and forming a heterogeneous structure layer by growing the plurality of deposited nuclei with a van der Waals epitaxial growth, wherein the heterogeneous structure layer is a single crystal.

An integrated circuit device includes an engineered substrate including a substantially single crystal layer and a buffer layer coupled to the substantially single crystal layer. The integrated circuit device also includes a plurality of semiconductor devices coupled to the buffer layer. The plurality of semiconductor devices can include a first power device coupled to a first portion of the buffer layer and a second power device coupled to a second portion of the buffer layer. The first power device includes a first channel region comprising a first end, a second end, and a first central portion disposed between the first end and the second end. The second power device includes a second channel region comprising a third end, a fourth end, and a second central portion disposed between the third end and the fourth end.

A substrate for group-III nitride epitaxial growth and a method for producing the same is capable of fabricating a high-quality group III nitride single crystal at low cost. The substrate for group-III nitride epitaxial growth includes: a supporting substrate having a structure in which a core consisting of nitride ceramics is wrapped in an encapsulating layer having a thickness of between 0.05 μm and 1.5 μm, inclusive; a planarizing layer provided on an upper surface of the supporting substrate, the planarizing layer having a thickness of between 0.5 μm and 3.0 μm, inclusive; and a seed crystal layer consisting of a single crystal with a thickness of between 0.1 μm and 1.5 μm, inclusive, provided on an upper surface planarizing layer and having an uneven pattern on the surface.

A method for manufacturing diamond substrate of using source gas containing hydrocarbon gas and hydrogen gas to form diamond crystal on an underlying substrate by CVD method, to form a diamond crystal layer having nitrogen-vacancy centers in at least part of the diamond crystal, nitrogen or nitride gas is mixed in the source gas, wherein the source gas is: 0.005 volume % or more and 6.000 volume % or less of the hydrocarbon gas; 93.500 volume % or more and less than 99.995 volume % of the hydrogen gas; and 5.0×10.sup.−5 volume % or more and 5.0×10.sup.−1 volume % or less of the nitrogen gas or the nitride gas, and the diamond crystal layer having the nitrogen-vacancy centers is formed. A method for manufacturing a diamond substrate to form an underlying substrate, a diamond crystal having a dense nitrogen-vacancy centers (NVCs) with an orientation of NV axis by performing the CVD.

A base substrate (1) for a group III-V compound crystal according to the present invention includes: a ceramic core layer (2); an impurity encapsulating layer (3) configured to encapsulate the ceramic core layer (2); a bonding layer (4) on the impurity encapsulating layer; and a processed layer (5) on the bonding layer. The impurity encapsulating layer (3) is a layer made of a composition represented by a composition formula SiOXNY (here, x=0 to 2, y=0 to 1.5, and x+y>0), the bonding layer (4) is a layer made of a composition represented by a composition formula SiO.sub.x′N.sub.y′ (here, x′=1 to 2, and y′=0 to 2, and the processed layer (5) is a seed crystal layer. According to the present invention, it is possible to provide the base substrate for a group III-V compound crystal and a method for producing the same for obtaining a group III-V compound crystal having a large diameter and high quality.

Provided are a structure for producing a high-quality single crystal diamond, and a method for manufacturing the structure for producing diamond. A structure for producing a diamond is composed of a base substrate and an Ir thin film formed on the base substrate. The thermal expansion coefficient of the base substrate is 5 times or less of the thermal expansion coefficient of diamond and the melting point of the base substrate is 700° C. or higher. The peak angle in the X-ray diffraction pattern of the Ir thin film is different from the peak angle in the X-ray diffraction pattern of the base substrate.

An epitaxial structure includes a substrate, a nucleation layer, a buffer layer, and a nitride layer. The nucleation layer is disposed on the substrate, and the nucleation layer consists of a plurality of regions in a thickness direction, wherein a chemical composition of the region is Al.sub.(1−x)In.sub.xN, where 0≤x≤1. The buffer layer is disposed on the nucleation layer, and a thickness of the nucleation layer is less than a thickness of the buffer layer. The nitride layer is disposed on the buffer layer, wherein 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.

A method for producing a Group III nitride crystal including preparing an RAMgO.sub.4 substrate containing a single crystal represented by the general formula RAMgO.sub.4 (wherein R represents one or a plurality of trivalent elements selected from the group consisting of Sc, In, Y, and a lanthanoid element, and A represents one or a plurality of trivalent elements selected from the group consisting of Fe(III), Ga, and Al); and growing a Group III nitride crystal containing Mg on the RAMgO.sub.4 substrate.

A semiconductor laminate at least including: a base; a buffer layer; and a crystalline metal oxide semiconductor film containing at least one metal element and having a corundum structure, the semiconductor laminate having the buffer layer on a main surface of the base directly or via another layer, the semiconductor laminate having the crystalline metal oxide semiconductor film on the buffer layer. The buffer layer is a laminate structure of a plurality of buffer films each with a different composition, and at least two buffer films of the plurality of buffer films have a film thickness of 200 nm or more and 650 nm or less.