A HEMT comprising a channel layer of a first III-Nitride semiconductor material, grown on a N-polar surface of a back barrier layer of a second III-Nitride semiconductor material; the second III-Nitride semiconductor material having a larger band gap than the first III-Nitride semiconductor material, such that a positively charged polarization interface and two-dimensional electron gas is obtained in the channel layer; a passivation, capping layer, of said first III-Nitride semiconductor material, formed on top of and in contact with a first portion of a N-polar surface of said channel layer; a gate trench traversing the passivation, capping layer, and ending at said N-polar surface of said channel layer; and a gate conductor filling said gate trench.

A transistor can include a substrate, an epitaxial oxide layer on the substrate, and a gate layer. The substrate can include a first crystalline material. The epitaxial oxide layer can include a second oxide material including: Li and one of Ni, Al, Ga, Mg, Zn and Ge; or Ni and one of Li, Al, Ga, Mg, Zn and Ge; or Mg and one of Ni, Al, Ga, and Ge; or Zn and one of Ni, Al, Ga, and Ge. The gate layer can include a third oxide material. A bandgap of the third oxide material of the gate can be wider than a bandgap of the second oxide material of the epitaxial oxide layer. The transistor can also include a source electrical contact coupled to the epitaxial oxide layer, a drain electrical contact coupled to the epitaxial oxide layer, and a first gate electrical contact coupled to the gate layer.

A method includes: providing a Group III nitride-based substrate having a first major surface and a doped Group III nitride region; forming a first passivation layer configured as a hydrogen diffusion barrier on the first major surface; forming a first opening in the first passivation layer and exposing at least a portion of the doped Group III nitride region from the first passivation layer; activating a first doped Group III nitride region whilst the first passivation layer is located on the first major surface and the doped Group III nitride region is at least partly exposed from the first passivation layer; forming a second passivation layer on the first passivation layer and on the doped Group III nitride region; forming a second opening in the first and second passivation layers and exposing a portion of the doped Group III nitride region; and forming a contact in the second opening.

A junction field effect transistor device includes a substrate, a well region, a first top layer, a plurality of source/drain regions, a first isolation structure, a gate, and a plurality of first well slots. The substrate has a first conductivity type. The well region is embedded in the substrate. The well region has a second conductivity type. The first top layer is embedded in the well region. The first top layer has the first conductivity type. The source/drain regions are disposed on a top surface of the well region. The first isolation structure is adjacent to one of the source/drain regions. The gate is disposed on a top surface of the first top layer. The first well slots are disposed below the gate. A second-conductivity-type dopant concentration of the first well slots is lower than a second-conductivity-type dopant concentration of the well region.

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 method for manufacturing a laser diode device includes providing a substrate having a surface region and forming epitaxial material overlying the surface region, the epitaxial material comprising an n-type cladding region, an active region comprising at least one active layer overlying the n-type cladding region, and a p-type cladding region overlying the active layer region. The epitaxial material is patterned to form a plurality of dice, each of the dice corresponding to at least one laser device, characterized by a first pitch between a pair of dice, the first pitch being less than a design width. Each of the plurality of dice are transferred to a carrier wafer such that each pair of dice is configured with a second pitch between each pair of dice, the second pitch being larger than the first pitch.

A semiconductor device includes a semiconductor body including a plurality of compound semiconductor layers and a two-dimensional charge carrier gas channel region formed in one of the compound semiconductor layers. The semiconductor device further includes a contact structure disposed in the semiconductor body. The contact structure includes a metal region and a doped region. The metal region extends into the semiconductor body from a first side of the semiconductor body to at least the compound semiconductor layer which includes the channel region. The doped region is formed in the semiconductor body between the metal region and the channel region so that the channel region is electrically connected to the metal region through the doped region.

A method of manufacturing a vertical junction field effect transistor (JFET) includes forming a drain in a semiconductor substrate, forming a compound semiconductor epitaxial layer on the semiconductor substrate, and forming a source, a gate, a drift region, and a body diode all in the same compound semiconductor epitaxial layer. The drain is vertically spaced apart from the source and the gate by the drift region. The body diode is connected between the drain and the source.

A method of manufacturing a semiconductor device includes forming electrode trenches in a semiconductor substrate between semiconductor mesas that separate the electrode trenches, the semiconductor mesas including portions of a drift layer of a first conductivity type and a body layer of a second, complementary conductivity type between a first surface of the semiconductor substrate and the drift layer, respectively. The method further includes forming isolated source zones of the first conductivity type in the semiconductor mesas, the source zones extending from the first surface into the body layer. The method also includes forming separation structures in the semiconductor mesas between neighboring source zones arranged along an extension direction of the semiconductor mesas, the separation structures forming partial or complete constrictions of the semiconductor mesa, respectively.

A JFET is formed with vertical and horizontal elements made from a high band-gap semiconductor material such as silicon carbide via triple implantation of a substrate comprising an upper drift region and a lower drain region, the triple implantation forming a lower gate, a horizontal channel, and an upper gate, in a portion of the drift region. A source region may be formed through a portion of the top gate, and the top and bottom gates are connected. A vertical channel region is formed adjacent to the planar JFET region and extending through the top gate, horizontal channel, and bottom gate to connect to the drift, such that the lower gate modulates the vertical channel as well as the horizontal channel, and current from the sources flows first through the horizontal channel and then through the vertical channel into the drift.