The structure and technology to improve the device performance of III-nitride semiconductor transistors at high drain voltage when the device is off is disclosed. P-type semiconductor regions are disposed between the gate electrode and the drain contact of the transistor structure. The P-type regions are electrically connected to the drain electrode. In some embodiments, the P-type regions are physically contacting the drain contact. In other embodiments, the P-type regions are physically separate from the drain contact, but electrically connected to the drain contact.

A method of manufacturing a semiconductor device includes: forming an electron transit layer; forming an electron supply layer; forming a protective film; forming a zinc oxide film; forming a sacrifice layer; forming a first opening and a second opening in the sacrifice layer and the zinc oxide film; forming a third opening connecting to the first opening and a fourth opening connecting to the second opening; forming, by acid treatment using a weakly acidic solution, a first gap in a first portion exposed to the first opening of the zinc oxide film, and a second gap in a second portion exposed to the second opening of the zinc oxide film; forming, after the acid treatment, a source region on a bottom surface of the third opening and a drain region on a bottom surface of the fourth opening; and removing the zinc oxide film.

A transistor device includes a semiconductor epitaxial layer structure including a channel layer and a barrier layer on the channel layer, wherein the barrier layer has a higher bandgap than the channel layer. A modified access region is provided at an upper surface of the barrier layer opposite the channel layer. The modified access region includes a material having a lower surface barrier height than the barrier layer. A source contact and a drain contact are formed on the barrier layer, and a gate contact is formed between source contact and the drain contact.

An apparatus includes a substrate; a group III-Nitride barrier layer; a source electrically coupled to the group III-Nitride barrier layer; a gate on the group III-Nitride barrier layer; a drain electrically coupled to the group III-Nitride barrier layer; a p-region being arranged at or below the group III-Nitride barrier layer; and a recovery enhancement circuit configured to reduce an impact of an overload received by the gate. Additionally, at least a portion of the p-region is arranged vertically below at least one of the following: the source, the gate, an area between the gate and the drain.

A field effect transistor comprising: a first semiconductor structure, the first semiconductor structure having a channel layer; a second semiconductor structure, the second semiconductor structure is arranged on the first semiconductor structure, and the second semiconductor structure is stacked in sequence from bottom to top with a Schottky layer, a first etch stop layer, a wide recess layer, an ohmic contact layer, and a narrow recess, a wide recess is opened in the ohmic contact layer, so that the upper surface of the wide recess layer forms a wide recess area and the upper surface of the Schottky layer forms a narrow recess area; at least one delta-doped layer, a gate metal contact, the gate metal contact is formed inside the wide recess a source metal contact; and a drain metal contact, and the drain metal contact is located on the other side of the gate metal contact.

The present disclosure provides a GaN-based semiconductor structure, including: a substrate; a channel layer; a barrier layer, where the channel layer and the barrier layer each include a channel region, a source region and a drain region; one or more grooves provided in at least one of the source region or the drain region, where, for each of the grooves, a length of a first side edge adjacent to the channel region and located on a bottom wall of the groove is larger than a length of an orthographic projection of the first side edge on a vertical plane in a length direction of the channel region; a source region N-type ion heavily-doped layer and a drain region N-type ion heavily-doped layer; and a gate electrode, a source electrode, and a drain electrode.

A transistor device includes a substrate and a gate structure. The gate structure is disposed on the substrate. The gate structure includes a first metal layer and a refractory metal layer disposed on the first metal layer, wherein the first metal layer is disconnected and the refractory metal layer is disconnected.

A transistor includes a semiconductor layer and a channel region. The transistor further includes a first doped contact region in the semiconductor layer and adjacent the channel region. The transistor further includes a first ohmic contact including an interface region comprising a first interface length between the first ohmic contact and the first doped contact region larger than a length of the interface region.

A high electron mobility transistor (HEMT) device with epitaxial layers that include a gallium nitride (GaN) layer co-doped with silicon (Si) and germanium Ge and a method of making the same is disclosed. The HEMT device includes a substrate with epitaxial layers over the substrate. An n-type gallium nitride (GaN) layer is disposed on an interface surface of the epitaxial layers, wherein the n-type GaN layer is co-doped with silicon (Si) and germanium (Ge) that provide a carrier concentration of at least 1×10.sup.20 cm.sup.−3 and a root mean square (RMS) surface roughness that is no greater than 2 nm for a contact surface of the n-type GaN layer that is interfaced with the interface surface of the epitaxial layers.

Systems and method are provided for depositing metal on GaN transistors after gate formation using a metal nitride Schottky gate. Embodiments of the present disclosure use a “diamond last” process using thermally stable metal nitride gate electrodes to enable thicker heat spreading films and facilitate process integration. In an embodiment, the “diamond last” process with high thermal conductivity diamond is enabled by the integration of thermally stable metal-nitride gate electrodes.