A surface-emitting laser element includes: a first guide layer including a photonic crystal layer that is formed on a c plane of a group-3 nitride semiconductor and includes air holes arranged with two-dimensional periodicity in a plane parallel to the photonic crystal layer, and an embedding layer that is formed on the photonic crystal layer and closes the air holes; an active layer formed on the first guide layer; and a second guide layer formed on the active layer, wherein an air hole set including at least a main air hole and a sub-air hole smaller in size than the main air hole is arranged at each square lattice point in the plane parallel to the photonic crystal layer, and wherein the main air hole has a regular-hexagonal prism shape, a long-hexagonal prism shape, or an elliptic cylindrical shape with a major axis parallel to a <11-20> axis.

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 transistor includes a channel layer, a gate stack, and source/drain regions. The channel layer includes a graphene layer and hexagonal boron nitride (hBN) flakes dispersed in the graphene layer. Orientations of the hBN flakes are substantially aligned. The gate stack is over the channel layer. The source/drain regions are aside the gate stack.

A method for manufacturing an III-nitride semiconductor structure is provided. The method includes providing a substrate comprising a first layer having an upper surface of monocrystalline III-nitride material; providing, over the upper surface, a patterned dielectric layer comprising a first dielectric feature; loading the substrate into a process chamber; exposing the substrate to a first gas mixture comprising at least one Group III-metal organic precursor gas, a nitrogen containing gas and hydrogen gas at a predetermined temperature, thereby forming, on the upper surface, a second layer of a monocrystalline III-nitride material by area selective growth wherein two opposing sidewalls of the dielectric feature are oriented parallel to one of the {11-20} crystal planes of the first layer such that upon formation of the second layer of the monocrystalline III-nitride material, a first trench having tapered sidewalls is formed so that the crystal plane of the second layer parallel to the tapered sidewalls is one of the {1-101} crystal planes.

A method includes providing a semiconductor structure having an active region and an isolation structure adjacent to the active region, the active region having source and drain regions sandwiching a channel region for a transistor, the semiconductor structure further having a gate structure over the channel region. The method further includes etching a trench in one of the source and drain regions, wherein the trench exposes a portion of a sidewall of the isolation structure, epitaxially growing a first semiconductor layer in the trench, epitaxially growing a second semiconductor layer over the first semiconductor layer, changing a crystalline facet orientation of a portion of a top surface of the second semiconductor layer by an etching process, and epitaxially growing a third semiconductor layer over the second semiconductor layer after the changing of the crystalline facet orientation.

Provided are dielectric thin-film structures and electronic devices including the same. The dielectric thin-film structure includes a substrate, and a dielectric layer provided on the substrate. The dielectric layer including a tetragonal crystal structure, and crystal grains including a proportion of the crystal grains preferentially oriented such that at least one of a <hk0>, <h00>, or <0k0> direction of a crystal lattice is parallel to or forms an angle of less than 45 degrees an out-of-plane orientation.

The present disclosure describes epitaxial oxide high electron mobility transistors (HEMTs). In some embodiments, a HEMT comprises: a substrate; a first epitaxial semiconductor layer on the substrate; and a second epitaxial semiconductor layer on the first epitaxial semiconductor layer. The first epitaxial semiconductor layer can comprise a first oxide material, wherein the first oxide material can comprise a first polar material with an orthorhombic, tetragonal or trigonal crystal symmetry, and wherein the first oxide material can comprise a first conductivity type formed via polarization. The second epitaxial semiconductor layer can comprise a second oxide material.

A method for preparation of orientation-patterned (OP) templates comprising the steps of: depositing a first layer of a first material on a common substrate by a far-from-equilibrium process; and depositing a first layer of a second material on the first layer of the first material by a close-to-equilibrium process, wherein a first assembly is formed. The first material and the second material may be the same material or different materials. The substrate material may be Al.sub.2O.sub.3 (sapphire), silicon (Si), germanium (Ge), GaAs, GaP, GaSb, InAs, InP, CdTe, CdS, CdSe, or GaSe. The first material deposited on the common substrate may be one or more electronic or optical binary materials from the group consisting of AlN, GaN, GaP, InP, GaAs, InAs, AlAs, ZnSe, GaSe, ZnTe, CdTe, HgTe, GaSb, SiC, CdS, CdSe, or their ternaries or quaternaries. The far-from-equilibrium process is one of MOCVD and MBE, and the close-to-equilibrium process is HVPE.

Problems associated with the mismatch between a silicon substrate and a group-IIIA nitride layer are addressed by employing a silicon substrate processed to have a surface comprising closely spaced tips extending from the surface, depositing a group-IIIB silicide layer on the tips, then depositing a group-IIIB nitride layer, and then depositing a group-IIIA nitride.

Methods of forming high voltage (111) silicon nano-structures are described. Those methods and structures may include forming a III-V device layer on (111) surface of a silicon fin structure, forming a 2DEG inducing polarization layer on the III-V device layer, forming a source/drain material on a portion of the III-V device layer on terminal ends of the silicon fin. A middle portion of the silicon fin structure between the source and drain regions may be removed, and backfilled with a dielectric material, and then a gate dielectric and a gate material may be formed on the III-V device layer.