A multilayer composite structure and a method of preparing a multilayer composite structure are provided. The multilayer composite structure comprises a semiconductor handle substrate having a minimum bulk region resistivity of at least about 500 ohm-cm and an isolation region that impedes the transfer of charge carriers along the surface of the handle substrate and reduces parasitic coupling between RF devices.

A method for manufacturing a semiconductor film includes placing a semiconductor substrate including a β-Ga.sub.2O.sub.3-based single crystal in a reaction chamber of an HVPE apparatus. When the semiconductor substrate is placed so that the growth base surface faces upward, an inlet for a dopant-including gas into the space is positioned higher than an inlet for an oxygen-including gas into the space and an inlet for a Ga chloride gas into the space is positioned higher than the inlet for the dopant-including gas into the space. When the semiconductor substrate is placed so that the growth base surface faces downward, the inlet for the dopant-including gas into the space is positioned higher than the inlet for the Ga chloride gas into the space and the inlet for the oxygen-including gas into the space is positioned higher than the inlet for the dopant-including gas into the space.

Methods and semiconductor structures are provided. A method according to the present disclosure includes forming, over a substrate, a fin-shaped structure that includes a plurality of channel layers interleaved by a plurality of sacrificial layers, recessing a source/drain region of the fin-shaped structure to form a source/drain recess that extends into the substrate and exposes a portion of the substrate, selectively and partially recessing sidewalls of the plurality of sacrificial layers to form inner spacer recesses, forming inner spacers in the inner spacer recesses, selectively forming a buffer semiconductor layer on the exposed portion of the substrate, selectively depositing a first epitaxial layer on sidewalls of the plurality of channel layer and the buffer semiconductor layer such that a top surface of the buffer semiconductor layer is completely covered by the first epitaxial layer, and depositing a second epitaxial layer over the first epitaxial layer and the inner spacers.

A reinforced thin-film device (100, 200, 500) including a substrate (101) having a top surface for supporting an epilayer; a mask layer (103) patterned with a plurality of nanosize cavities (102, 102′) disposed on said substrate (101) to form a needle pad; a thin-film (105) of lattice-mismatched semiconductor disposed on said mask layer (103), wherein said thin-film (105) comprises a plurality of in parallel spaced semiconductor needles (104, 204) of said lattice-mismatched semiconductor embedded in said thin-film (105), wherein said plurality of semiconductor needles (104, 204) are substantially vertically disposed in the axial direction toward said substrate (101) in said plurality of nanosize cavities (102, 102′) of said mask layer (103), and where a lattice-mismatched semiconductor epilayer (106) is provided on said thin-film supported thereby.

A method of forming a semiconductor device comprises forming sacrificial structures and support pillars on a material. Tiers are formed over the sacrificial structures and support pillars and tier pillars and tier openings are formed to expose the sacrificial structures. One or more of the tier openings comprises a greater critical dimension than the other tier openings. The sacrificial structures are removed to form a cavity. A cell film is formed over sidewalls of the tier pillars, the cavity, and the one or more tier openings. A fill material is formed in the tier openings and adjacent to the cell film and a portion removed from the other tier openings to form recesses adjacent to an uppermost tier. Substantially all of the fill material is removed from the one or more tier openings. A doped polysilicon material is formed in the recesses and the one or more tier openings. A conductive material is formed in the recesses and in the one or more tier openings. An opening is formed in a slit region and a dielectric material is formed in the opening. Additional methods, semiconductor devices, and systems are disclosed.

In a method of manufacturing a semiconductor device, a gate structure is formed over a fin structure. A source/drain region of the fin structure is recessed. A first semiconductor layer is formed over the recessed source/drain region. A second semiconductor layer is formed over the first semiconductor layer. The fin structure is made of Si.sub.xGe.sub.1-x, where 0≤x≤0.3, the first semiconductor layer is made of Si.sub.yGe.sub.1-y, where 0.45≤y≤1.0, and the second semiconductor layer is made of Si.sub.zGe.sub.1-z, where 0≤z≤0.3.

The present disclosure is directed to semiconductor structures with source/drain epitaxial stacks having a low-melting point top layer and a high-melting point bottom layer. For example, a semiconductor structure includes a gate structure disposed on a fin and a recess formed in a portion of the fin not covered by the gate structure. Further, the semiconductor structure includes a source/drain epitaxial stack disposed in the recess, where the source/drain epitaxial stack has bottom layer and a top layer with a higher activated dopant concentration than the bottom layer.

Fabricating a regrown GaN p-n junction includes depositing a n-GaN layer on a substrate including n.sup.+-GaN, etching a surface of the n-GaN layer to yield an etched surface, depositing a p-GaN layer on the etched surface, etching a portion of the n-GaN layer and a portion of the p-GaN layer to yield a mesa opposite the substrate, and passivating a portion of the p-GaN layer around an edge of the mesa. The regrown GaN p-n junction is defined at an interface between the n-GaN layer and the p-GaN layer. The regrown GaN p-n junction includes a substrate, a n-GaN layer on the substrate having an etched surface, a p-GaN layer on the etched surface, a mesa defined by an etched portion of the n-GaN layer and an etched portion of the p-GaN layer, and a passivated portion of the p-GaN layer around an edge of the mesa.

A group III nitride crystal, wherein the group III nitride crystal is doped with an N-type dopant and a germanium element, the concentration of the N-type dopant is 1×10.sup.19 cm.sup.−3 or more, and the concentration of the germanium element is nine times or more higher than the concentration of the N-type dopant.

Disclosed are an MPS diode device and a preparation method therefor. The MPS diode device comprises a plurality of cells arranged in parallel, wherein each cell comprises a cathode electrode, and a substrate, epitaxial layer, buffer layer, and anode electrode that are formed in succession on the cathode electrode; two active regions are formed on the side of the epitaxial layer away from the substrate; the width of forbidden band of the buffer layer is greater than the width of forbidden band of the epitaxial layer, and a material of the buffer layer and a material of the epitaxial layer are allotropes; and first openings are formed at the positions in the buffer layer opposite to the active regions, and an ohmic metal layer is formed in the first openings.