[Overview] [Problem to be Solved] To provide a switching transistor and a semiconductor module having lower distortion generated in a signal. [Solution] A switching transistor including: a channel layer including a compound semiconductor and having sheet electron density equal to or higher than 1.7×10.sup.13 cm.sup.−2; a barrier layer formed on the channel layer by using a compound semiconductor that is of a different type from the channel layer; a gate electrode provided on the barrier layer; and a source electrode and a drain electrode provided on the barrier layer with the gate electrode interposed between the source electrode and the drain electrode.

Disclosed herein are devices, systems and methods useful for downhole sensors and electronics suitable for harsh thermal and mechanical environment associated with high-temperature geothermal drilling and high-temperature/high-pressure oil and gas drilling.

The semiconductor device has a barrier layer formed on a channel layer, an n type diffusion preventing layer formed on the barrier layer and containing aluminum, and a source electrode and a drain electrode formed on the diffusion preventing layer. The semiconductor device further has a p type cap layer formed on the diffusion preventing layer sandwiched between the source electrode and the drain electrode and a gate electrode formed on the cap layer. The diffusion preventing layer has an aluminum composition ratio greater than the aluminum composition ratio of the barrier layer.

A Group III-nitride-based enhancement mode transistor includes a multi-heterojunction fin structure. A first side face of the multi-heterojunction fin structure is covered by a first p-type Group III-nitride layer, and a second side face of the multi-heterojunction fin structure is covered by a second p-type Group III-nitride layer.

A field effect transistor (FET) including a substrate, a plurality of semiconductor epitaxial layers deposited on the substrate, and a heavily doped gate layer deposited on the semiconductor layers. The FET also includes a plurality of castellation structures formed on the heavily doped gate layer and being spaced apart from each other, where each castellation structure includes at least one channel layer. A gate metal is deposited on the castellation structures and between the castellation structures to be in direct electrical contact with the heavily doped gate layer. A voltage potential applied to the gate metal structure modulates the at least one channel layer in each castellation structure from an upper, lower and side direction.

According to one embodiment, a semiconductor device includes first to third electrodes, first to third nitride regions, and first and second insulating films. The first nitride region includes Al.sub.x1Ga.sub.1−x1N, and includes first and second partial regions, a third partial region between the first and second partial regions, a fourth partial region between the first and third partial regions, and a fifth partial region between the third and second partial regions. The first nitride region includes first to fifth partial regions. The second nitride region includes Al.sub.x2Ga.sub.1−x2N, and sixth and seventh partial regions. At least a portion of the third electrode is between the sixth and seventh partial regions. The first insulating film includes silicon and oxygen and includes first and second insulating regions. The third nitride region includes Al.sub.x3Ga.sub.1−x3N, and first to seventh portions. The second insulating film includes silicon and oxygen and includes third to seventh insulating regions.

A substrate includes a support structure comprising a polycrystalline ceramic core, a first adhesion layer encapsulating the polycrystalline ceramic core, a barrier layer encapsulating the first adhesion layer, a second adhesion layer coupled to the barrier layer, and a conductive layer coupled to the second adhesion layer. The substrate also includes a bonding layer coupled to the support structure, a substantially single crystal silicon layer coupled to the bonding layer, and an epitaxial semiconductor layer coupled to the substantially single crystal silicon layer.

A semiconductor high electron mobility transistor (HEMT)-based device configured to detect ionizing radiation, wherein the device comprises: a substrate; a nucleation layer formed on the substrate; a gallium nitride (GaN) buffer layer arranged on the nucleation layer; a GaN channel layer arranged on the GaN buffer layer; an aluminum nitride (A1N) spacer layer arranged on the GaN channel layer; a barrier layer arranged on the A1N spacer layer; a GaN cap layer arranged on the barrier layer; an electrically insulating silicon nitride (SiNx) passivation layer arranged on the GaN cap layer; a source, a drain and a gate, wherein the source and the drain are formed on the GaN cap layer; wherein charge carriers generated by the radiation in the underlying GaN layers are collected in the GaN channel layer and multiplied by impact ionization by a high electric field at the gate edge facing the drain contact.

A superconductor transistor structure includes a source electrode and a drain electrode on a same plane as the source electrode. There is a channel region on top of the source and drain electrodes and configured to carry a current. A gate structure comprising a metallic material is on top of the channel region. The source and drain are located on a side that is opposite to that of the gate structure, with respect to the channel region.

A transistor device includes a semiconductor layer, a surface dielectric layer on the semiconductor layer, and at least a portion of a gate on the surface dielectric layer. The surface dielectric layer includes an aperture therein that is laterally spaced apart from the gate. The transistor device includes an interlayer dielectric layer on the surface dielectric layer, and a field plate on the interlayer dielectric layer. The field plate is laterally spaced apart from the gate, and at least a portion of the field plate includes a recessed portion above the aperture in the surface dielectric layer.