A transistor having at least one passivated Schottky barrier to a channel includes an insulated gate structure on a p-type substrate in which the channel is located beneath the insulated gate structure. The channel and the insulated gate structure define a first and second undercut void regions that extend underneath the insulated gate structure toward the channel from a first and a second side of the insulated gate structure, respectively. A passivation layer is included on at least one exposed sidewall surface of the channel and metal source and drain terminals are located on respective first and second sides of the channel, including on the passivation layer and within the undercut void regions beneath the insulated gate structure. At least one of the metal source and drain terminals comprises a metal that has a work function near a valence band of the p-type substrate.

A nitride semiconductor device according to the present disclosure includes a substrate, a p-type GaN layer formed on a main surface of the substrate and made of Al.sub.xIn.sub.yGa.sub.1-x-yN containing p-type impurities, where 0X<1, 0Y<1, and a Ti film formed on the p-type GaN layer. The Ti film is in a coherent or metamorphic state with respect to the p-type GaN layer.

A semiconductor device includes: a substrate; a nitride semiconductor layer on the substrate; a source electrode, a drain electrode and a gate electrode on the nitride semiconductor layer; and a SiN surface protective film covering the nitride semiconductor layer, wherein a composition ratio Si/N of Si and N that form a SiN bond of the SiN surface protective film is 0.751 to 0.801

A low leakage current switch device (110) is provided which includes a GaN-on-Si substrate (11, 13) with one or more device mesas (41) in which isolation regions (92, 93) are formed using an implant mask (81) to implant ions (91) into an upper portion of the mesa sidewalls and the peripheral region around each elevated surface of the mesa structures exposed by the implant mask, thereby preventing the subsequently formed gate electrode (111) from contacting the peripheral edge and sidewalls of the mesa structures.

Provided is a crystalline multilayer structure having good semiconductor properties. In particular, the crystalline multilayer structure has good electrical properties as follows: the controllability of conductivity is good; and vertical conduction is possible. A crystalline multilayer structure includes a metal layer containing a uniaxially oriented metal as a major component and a semiconductor layer disposed directly on the metal layer or with another layer therebetween and containing a crystalline oxide semiconductor as a major component. The crystalline oxide semiconductor contains one or more metals selected from gallium, indium, and aluminum and is uniaxially oriented.

A multi-gate transistor includes a semiconductor fin over a substrate. The semiconductor fin includes a central fin formed of a first semiconductor material; and a semiconductor layer having a first portion and a second portion on opposite sidewalls of the central fin. The semiconductor layer includes a second semiconductor material different from the first semiconductor material. The multi-gate transistor further includes a gate electrode wrapping around sidewalls of the semiconductor fin; and a source region and a drain region on opposite ends of the semiconductor fin. Each of the central fin and the semiconductor layer extends from the source region to the drain region.

A high frequency semiconductor device includes a stacked body, a gate electrode, a source electrode and a drain electrode. The gate electrode includes a bending gate part and a straight gate part. The bending gate part is extended in a zigzag shape and has first and second outer edges. The source electrode includes a bending source part and a straight source part. The bending source part has an outer edge spaced by a first distance from the first outer edge of the bending gate part along a normal direction. The drain electrode includes a bending drain part and a straight drain part. The bending drain part has an outer edge spaced by a second distance from the second outer edge of the bending gate part along the normal direction.

In an embodiment, a Group III nitride-based transistor device is provided that includes a Group III nitride-based body and a p-type Schottky gate including a metal gate on a p-doped Group III nitride structure. The p-doped Group III nitride structure includes an upper p-doped GaN layer in contact with the metal gate and having a thickness d.sub.1, a lower p-doped Group III nitride layer having a thickness d.sub.2 and including p-doped GaN that is arranged on and in contact with the Group III nitride-based body, and at least one p-doped Al.sub.xGa.sub.1xN layer arranged between the upper p-doped GaN layer and the lower p-doped Group III nitride layer, wherein 0<x<1. The thickness d.sub.2 of the lower p-doped Group III nitride layer is larger than the thickness d.sub.1 of the upper p-doped GaN layer.

A SiC junction field effect transistor includes a SiC substrate, a first conductivity type channel region formed in the principal surface of the SiC substrate, a second conductivity type embedded gate region formed below the channel region on the principal surface side in the SiC substrate, and first conductivity type source region and drain region formed with the channel region interposed therebetween in the principal surface of the SiC substrate.

A semiconductor structure is disclosed. The semiconductor structure includes: a substrate; a plurality of gate conductive patterns on the substrate; an interlayer dielectric layer covering the gate conductive patterns on the substrate; an interconnect structure comprising a contact plug and a first contact pad, the contact plug extending through the interlayer dielectric layer to the substrate, the first contact pad fully covering a top of the contact plug and extending laterally over part of a top surface of the interlayer dielectric layer; and a second contact pad formed on the top surface of the interlayer dielectric layer and spaced apart from a side edge of the first contact pad, wherein the second contact pad is formed and fully overlays on the interlayer dielectric layer and an isolation plug is spaced apart from the first contact pad.