The present disclosure describes epitaxial oxide high electron mobility transistors (HEMTs). In some embodiments, a HEMT comprises: a substrate; a template layer on the substrate; a first epitaxial semiconductor layer on the template layer; and a second epitaxial semiconductor layer on the first epitaxial semiconductor layer. The template layer can comprise crystalline metallic Al(111). The first epitaxial semiconductor layer can comprise (Al.sub.xGa.sub.1-x).sub.yO.sub.z, wherein 0≤x≤1, 1≤y≤3, and 2≤z≤4, wherein the (Al.sub.xGa.sub.1-x).sub.yO.sub.z comprises a Pna21 space group, and wherein the (Al.sub.xGa.sub.1-x).sub.yO.sub.z comprises a first conductivity type formed via polarization. The second epitaxial semiconductor layer can comprise a second oxide material.

A method for making a semiconductor gate-all-around (GAA) device may include forming source and drain regions on a semiconductor substrate, forming a plurality of semiconductor nanostructures extending between the source and drain regions, and forming a gate surrounding the plurality of semiconductor nanostructures in a gate-all-around arrangement. Furthermore, the method may include forming at least one superlattice may be within at least one of the nanostructures. The at least one superlattice may include a plurality of stacked groups of layers, with each group of layers including a plurality of stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions.

Epitaxial growth of materials, and related systems and articles, are generally described.

The present disclosure provides a radio frequency device, a silicon carbide homoepitaxial substrate and a manufacturing method thereof. The manufacturing method of the silicon carbide homoepitaxial substrate includes: providing an N-type silicon carbide substrate, forming first grooves in the N-type silicon carbide substrate; forming a defect repair layer on inner walls of the first grooves and outside the first grooves, and forming second grooves in the defect repair layer corresponding to the first grooves; forming an unintentionally doped silicon carbide layer on the defect repair layer, where the second grooves are fully filled with the unintentionally doped silicon carbide layer.

The present invention provides materials, structures, and methods for III-nitride-based devices, including epitaxial and non-epitaxial structures useful for III-nitride devices including light emitting devices, laser diodes, transistors, detectors, sensors, and the like. In some embodiments, the present invention provides metallo-semiconductor and/or metallo-dielectric devices, structures, materials and methods of forming metallo-semiconductor and/or metallo-dielectric material structures for use in semiconductor devices, and more particularly for use in III-nitride based semiconductor devices. In some embodiments, the present invention includes materials, structures, and methods for improving the crystal quality of epitaxial materials grown on non-native substrates. In some embodiments, the present invention provides materials, structures, devices, and methods for acoustic wave devices and technology, including epitaxial and non-epitaxial piezoelectric materials and structures useful for acoustic wave devices. In some embodiments, the present invention provides metal-base transistor devices, structures, materials and methods of forming metal-base transistor material structures for use in semiconductor devices.

A semiconductor device includes a substrate, a semiconductor structure suspending over the substrate and comprising a source region, a drain region, and a channel region disposed between the source region and the drain region. The channel region includes a doped two-dimensional (2D) material layer comprising a first portion on an upper surface of the channel region. The semiconductor device also includes an interfacial layer surrounding the channel region including the first portion of the doped 2D material layer, and and a gate electrode surrounding the interfacial layer.

A method for making a semiconductor device may include forming a superlattice above a semiconductor layer. The superlattice may include a plurality of stacked groups of layers, with each group of layers including a plurality of stacked base semiconductor monolayers defining a base semiconductor portion and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions. The method may further include selectively etching the superlattice to remove semiconductor atoms and cause non-semiconductor atoms to accumulate and define an etch stop layer.

A vertical semiconductor device may include a semiconductor substrate having at least one trench therein, and a superlattice layer extending vertically adjacent the at least one trench. The superlattice layer may comprise stacked groups of layers, with each group of layers comprising stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer. Each at least one non-semiconductor monolayer of each group of layers may be constrained within a crystal lattice of adjacent base semiconductor portions. The vertical semiconductor device may also include a doped semiconductor layer adjacent the superlattice layer, and a conductive body adjacent the doped semiconductor layer on a side thereof opposite the superlattice layer and defining a vertical semiconductor device contact.

A method for making a semiconductor device may include forming an inverted T channel on a substrate, with the inverted T channel comprising a superlattice. The superlattice may include a plurality of stacked groups of layers, with each group of layers comprising a plurality of stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions. The method may further include forming source and drain regions on opposing ends of the inverted T channel, and forming a gate overlying the inverted T channel between the source and drain.

Semiconductor structures and methods for forming those semiconductor structures are disclosed. For example, a semiconductor structure with a p-type superlattice region, an i-type superlattice region, and an n-type superlattice region is disclosed. The semiconductor structure can have a polar crystal structure with a growth axis that is substantially parallel to a spontaneous polarization axis of the polar crystal structure. In some cases, there are no abrupt changes in polarisation at interfaces between each region. At least one of the p-type superlattice region, the i-type superlattice region and the n-type superlattice region can comprise a plurality of unit cells exhibiting a monotonic change in composition from a wider band gap (WBG) material to a narrower band gap (NBG) material or from a NBG material to a WBG material along the growth axis to induce p-type or n-type conductivity.