In some examples, a transistor comprises a gallium nitride (GaN) layer; a GaN-based alloy layer having a top side and disposed on the GaN layer, wherein source, drain, and gate contact structures are supported by the GaN layer; and a first doped region positioned in a drain access region and extending from the top side into the GaN layer.

A semiconductor device includes a semiconductor layer that is of a first conductivity type, a body region of a second conductivity type, a source region to be separated inwardly from an outer edge of the body region, a drain region formed on a surface of the semiconductor layer so as to be separated from the body region in a first direction orthogonal to a thickness direction of the semiconductor layer, a gate insulating layer formed on a portion of the surface of the semiconductor layer between the source region and the drain region in the first direction, a gate electrode that is formed on the gate insulating layer, an exposed region that is formed in the body region at a different position from the source region and in which the semiconductor layer is exposed, and a metal layer that forms a Schottky junction with the exposed region.

A structure having: a plurality of field effect transistors (FETs) connected between a common input and a common output, each one of the field effect transistors comprises: a source region, a drain region, and a gate electrode for controlling carriers through a channel region of a transistor region of the structure between the source region and the drain region; a plurality of diodes, each one of the diodes being associated with a corresponding one of the plurality of FETs, each one of the diodes having an electrode in Schottky contact with a diode region of the corresponding one of the FETs. The gate electrode and the diode electrode extend along parallel lines. The source region, the drain region, the channel region, and a diode region having therein the diode are disposed along a common line.

A structure having: a plurality of field effect transistors (FETs) connected between a common input and a common output, each one of the field effect transistors comprises: a source region, a drain region, and a gate electrode for controlling carriers through a channel region of a transistor region of the structure between the source region and the drain region; a plurality of diodes, each one of the diodes being associated with a corresponding one of the plurality of FETs, each one of the diodes having an electrode in Schottky contact with a diode region of the corresponding one of the FETs. The gate electrode and the diode electrode extend along parallel lines. The source region, the drain region, the channel region, and a diode region having therein the diode are disposed along a common line.

In some examples, a transistor comprises a gallium nitride (GaN) layer; a GaN-based alloy layer having a top side and disposed on the GaN layer, wherein source, drain, and gate contact structures are supported by the GaN layer, and a first doped region positioned in a drain access region and extending from the top side into the GaN layer.

A HEMT transistor has a semiconductor layer structure that comprises a Group III nitride-based channel layer and a higher bandgap Group III nitride-based barrier layer on the channel layer. A gate finger and first and second source/drain contacts are provided on the semiconductor layer structure. A first source/drain region is provided in the semiconductor layer structure that includes a first implanted region that is underneath the first source/drain contact and a first auxiliary implanted region. A depth of the first implanted region is at least twice a depth of the first auxiliary implanted a region. The first source/drain region extends inwardly a first distance from a lower edge of an inner sidewall of the first source/drain contact, and extends outwardly a second smaller distance from a lower edge of an outer sidewall of the first source/drain contact.

A structure having: a plurality of field effect transistors (FETs) connected between a common input and a common output, each one of the field effect transistors comprises: source region, a drain region, and a gate electrode for controlling carriers through a channel region of a transistor region of the structure between the source region and the drain region; a plurality of diodes, each one of the diodes being associated with a corresponding one of the plurality of FETs, each one of the diodes having an electrode in Schottky contact with a diode region of the corresponding one of the FETs. The gate electrode and the diode electrode extend along parallel lines. The source region, the drain region, the channel region, and a diode region having therein the diode are disposed along a common line.

The switching device includes an electron transport layer; an electron supply layer provided on the electron transport layer and being in contact with the electron transport layer by heterojunction; a source electrode being in contact with the electron supply layer; a drain electrode being in contact with the electron supply layer at a position spaced from the source electrode; and a first gate electrode provided above the electron supply layer, and provided between the source electrode and the drain electrode when viewed in a plan view from above. The first gate electrode is electrically connected above the electron supply layer to the drain electrode. An on-resistance of the switching device is lower than an electric resistance between the first gate electrode and the drain electrode.

In an embodiment, a semiconductor device includes an enhancement mode Group III-nitride-based High Electron Mobility Transistor (HEMT) including a drain, a gate, a barrier layer, a channel layer, a barrier layer arranged on the channel layer, and a heterojunction formed between the barrier layer and the channel layer and capable of supporting a two-dimensional electron gas (2DEG). At least one of a thickness and a composition of the barrier layer is configured to decrease a 2DEG density in a channel region compared with a 2DEG density outside of the channel region, wherein the channel region is arranged under the gate and extends a distance d beyond a drain-sided gate edge.

A semiconductor device includes: a substrate; a nitride semiconductor film on the substrate; a schottky electrode on the nitride semiconductor film; a first insulating film on the nitride semiconductor film, contacting at least part of a side surface of the schottky electrode, forming an interface with the nitride semiconductor film and formed of SiN; and a second insulating film covering the schottky electrode and the first insulating film and formed of AlO whose atomic layers are alternately disposed.