A substrate comprising a III-N base layer comprising a first portion and a second portion, the first portion of the III-N base layer having a first natural lattice constant and a first dislocation density; and a first III-N layer having a second natural lattice constant and a second dislocation density on the III-N base layer, the first III-N layer having a thickness greater than 10 nm. An indium fractional composition of the first III-N layer is greater than 0.1; the second natural lattice constant is at least 1% greater than the first natural lattice constant; a strain-induced lattice constant of the first III-N layer is greater than 1.0055 times the first natural lattice constant; and the second dislocation density is less than 1.5 times the first dislocation density.

A semiconductor device and fabricating method thereof is disclosed. The method comprises depositing epitaxial layers over a silicon substrate to form a semiconductor layer surface; forming at least one mesa portion on the semiconductor layer surface; depositing a metal stack on the semiconductor layer surface; subjecting the semiconductor layer surface to a rapid thermal annealing system for a two-step ohmic contact annealing in H.sub.2/N.sub.2 forming gas (FG) and then nitrogen; subjecting the semiconductor layer surface to an oxygen plasma treatment; and depositing a T-shaped metal gate on the semiconductor layer surface. A semiconductor device comprises a semiconductor layer surface having an epitaxial layer disposed over a silicon substrate; at least one mesa portion formed on the semiconductor layer surface; a metal stack, disposed on the semiconductor layer surface, and sequentially annealed in FG and nitrogen; and a T-shaped metal gate on the semiconductor layer surface.

An integrated circuit structure comprises a silicon substrate and a III-nitride (III-N) substrate over the silicon substrate. A first III-N transistor and a second III-N transistor is on the III-N substrate. An insulator structure is formed in the III-N substrate between the first III-N transistor and the second III-N, wherein the insulator structure comprises one of: a shallow trench filled with an oxide, nitride or low-K dielectric; or a first gap adjacent to the first III-N transistor and a second gap adjacent to the second III-N transistor.

A composite substrate is provided in some embodiments of the present disclosure, which includes a substrate, an insulation layer, a first silicon-containing layer and a first epitaxial layer. The insulation layer is disposed on the substrate. The first silicon-containing layer is disposed on the insulation layer, in which the first silicon-containing layer includes a plurality of group V atoms. The first epitaxial layer is disposed on the first silicon-containing layer, in which the first epitaxial layer includes a plurality of group III atoms. A distribution concentration of the group V atoms in the first silicon-containing layer increases as getting closer to the first epitaxial layer, and a distribution concentration of the group III atoms in the first epitaxial layer increases as getting closer to the first silicon-containing layer. A method of manufacturing a composite substrate is also provided in some embodiments of the present disclosure.

A high electron mobility transistor (HEMT) device and a method of forming the same are provided. The method includes forming a first III-V compound layer over a substrate. A second III-V compound layer is formed over the first III-V compound layer. The second III-V compound layer has a greater band gap than the first III-V compound layer. A third III-V compound layer is formed over the second III-V compound layer. The third III-V compound layer and the first III-V compound layer comprise a same III-V compound. A passivation layer is formed along a topmost surface and sidewalls of the third III-V compound layer. A fourth III-V compound layer is formed over the second III-V compound layer. The fourth III-V compound layer has a greater band gap than the first III-V compound layer.

III-Nitride heterostructures with low p-type sheet resistance and III-Nitride heterostructure devices with gate recess and devices including the III-Nitride heterostructures are disclosed.

Provided are a method for preparing an InGaN-based epitaxial layer on a Si substrate (12), as well as a silicon-based InGaN epitaxial layer prepared by the method. The method may include the steps of: 1) directly growing a first InGaN-based layer (11) on a Si substrate (12); and 2) growing a second InGaN-based layer on the first InGaN-based layer (11).

An electrostatically controlled sensor includes a GaN/AlGaN heterostructure having a 2DEG channel in the GaN layer. Source and drain contacts are electrically coupled to the 2DEG channel through the AlGaN layer. A gate dielectric is formed over the AlGaN layer, and gate electrodes are formed over the gate dielectric, wherein each gate electrode extends substantially entirely between the source and drain contacts, wherein the gate electrodes are separated by one or more gaps (which also extend substantially entirely between the source and drain contacts). Each of the one or more gaps defines a corresponding sensing area between the gate electrodes for receiving an external influence. A bias voltage is applied to the gate electrodes, such that regions of the 2DEG channel below the gate electrodes are completely depleted, and regions of the 2DEG channel below the one or more gaps in the direction from source to drain are partially depleted.

Porous III-nitrides having controlled/tuned optical, electrical, and thermal properties are described herein. Also disclosed are methods for preparing and using such porous III-nitrides.

The present disclosure provides a semiconductor device and a fabrication method thereof. The semiconductor device includes a substrate, a first nitride semiconductor layer, a second nitride semiconductor layer, and a carbonitride semiconductor layer. The first nitride semiconductor layer is over the substrate. The second nitride semiconductor layer is formed on the first nitride semiconductor layer and has a greater bandgap than that of the first nitride semiconductor layer. The carbonitride semiconductor layer is between the substrate and the first nitride semiconductor layer.