A semiconductor device is provided, including a substrate, a gate electrode, a first dielectric layer, a source field plate, a second dielectric layer, a source electrode and a drain electrode. The gate electrode is disposed on the substrate. The first dielectric layer is disposed on the gate electrode and has a first recess and a second recess. The source field plate is disposed on the first dielectric layer and extends into the first recess and the second recess. The second dielectric layer is disposed on the source field plate. The source electrode is disposed on the second dielectric layer and electrically connected to the source field plate. The drain electrode is disposed on the second dielectric layer. The first recess and the second recess are located between the gate electrode and the drain electrode.

A process of forming a nitride semiconductor device is disclosed. The process includes steps of: (a) forming insulating films on a semiconductor stack, where the insulating films include a first silicon nitride (SiN) film, a silicon oxide (SiO.sub.2) film, and a second SiN film; (b) forming an opening in the insulating films; (c) widening the opening in the SiO.sub.2 film; (d) forming a recess in the semiconductor stack using the insulating films as a mask; (e) growing a doped region within the recess and simultaneously depositing the nitride semiconductor material constituting the doped region on the second SiN film; and (f) removing the nitride semiconductor material deposited on the second SiN film and the second SiN film by removing the SiO.sub.2 film.

A semiconductor device is described. In one embodiment, the device includes a Group-III nitride channel layer and a Group-III nitride barrier layer on the Group-III nitride channel layer, wherein the Group-III nitride barrier layer includes a first portion and a second portion, the first portion having a thickness less than the second portion. A p-doped Group-III nitride gate layer section is arranged at least on the first portion of the Group-III nitride barrier layer and a gate contact formed on the p-doped Group-III nitride gate layer.

Field-effect transistors (FETs) are described that comprise a semiconducting gate (SG) layer, referred to herein as SG-FETs. In one or more embodiments, the FETs can include a channel layer and a SG layer capacitively coupled to the channel layer. The SG layer has an embedded voltage-clamping function that provides internal gate over voltage protection without an additional protection circuit. The embedded voltage-clamping function is based on the SG layer having a maximum effective gate voltage that is clamped to the depletion threshold of the SG layer.

A method of forming a high electron mobility transistor (HEMT) includes a first III-V compound layer and a second III-V compound layer disposed on the first III-V compound layer and is different from the first III-V compound layer in composition. A source feature and a drain feature are disposed on the second III-V compound layer. A p-type layer is disposed on a portion of the second III-V compound layer between the source feature and the drain feature. A gate electrode is disposed on the p-type layer. A capping layer is disposed on the second III-V compound layer.

A gate stack structure is disclosed for inhibiting charge leakage in III-V transistor devices. The techniques are particularly well-suited for use in enhancement-mode MOSHEMTs but can also be used in other transistor designs susceptible to charge spillover and unintended channel formation in the gate stack. In an example embodiment, the techniques are realized in a transistor having a III-N gate stack over a gallium nitride (GaN) channel layer. The gate stack is configured with a relatively thick barrier structure and wide bandgap III-N materials to prevent or otherwise reduce channel charge spillover resulting from tunneling or thermionic processes at high gate voltages. The barrier structure is configured to manage lattice mismatch conditions, so as to provide a robust high-performance transistor design. In some cases, the gate stack is used in conjunction with an access region polarization layer to induce two-dimensional electron gas (2DEG) in the channel layer.

A high electron mobility transistor (HEMT) includes a substrate, a P-type III-V composition layer, a gate electrode and a carbon containing layer. The P-type III-V composition layer is disposed on the substrate, and the gate electrode is disposed on the P-type III-V composition layer. The carbon containing layer is disposed under the P-type III-V composition layer to function like an out diffusion barrier for preventing from the dopant within the P-type III-V composition layer diffusing into the stacked layers underneath during the annealing process.

Dielectric super-junction transistors use combinations high dielectric relative permittivity materials and high-mobility materials. An associated electronic device includes a junction portion of a barrier layer adjacent a gate contact and a drain contact. A layered semiconductor device is configured with a junction dielectric permittivity that is greater than a channel dielectric permittivity in the channel layer. The junction portion has a dielectric structure that polarizes carriers within the junction portion such that excess charge on the gate is compensated by an opposite charge in the junction portion of the barrier layer proximate the gate. A sheet charge in the barrier layer is increased to form a depletion region with the channel layer that avoids a conductive parallel channel in the barrier layer to the drain contact.

A semiconductor device comprising an N-type metal oxide semiconductor (NMOS) gate-all-around (GAA) transistor and a P-type metal oxide semiconductor (PMOS) GAA transistor with high charge mobility channel materials is disclosed. The semiconductor device may include a substrate. The semiconductor device may also include an NMOS GAA transistor on the substrate, wherein the NMOS GAA transistor comprises a first channel material. The semiconductor device may further include a PMOS GAA transistor on the substrate, wherein the PMOS GAA transistor comprises a second channel material. The first channel material may have an electron mobility greater than an electron mobility of Silicon (Si) and the second channel material may have a hole mobility greater than a hole mobility of Si.

A disclosed semiconductor device includes an electron transit layer; an electron supply layer disposed on or above the electron transit layer; and a capping layer disposed on or above the electron supply layer, wherein a first lattice constant of the electron transit layer is greater than a second lattice constant of the electron supply layer in a direction parallel to a main surface of the electron transit layer.