A semiconductor device that includes a fin structure of a type III-V semiconductor material that is substantially free of defects, and has sidewalls that are substantially free of roughness caused by epitaxially growing the type III-V semiconductor material abutting a dielectric material. The semiconductor device further includes a gate structure present on a channel portion of the fin structure; and a source region and a drain region present on opposing sides of the gate structure.

A termination structure for a nitride-based Schottky diode includes a guard ring formed by an epitaxially grown P-type nitride-based compound semiconductor layer and dielectric field plates formed on the guard ring. The termination structure is formed at the edge of the anode electrode of the Schottky diode and has the effect of reducing electric field crowding at the anode electrode edge, especially when the Schottky diode is reverse biased. In one embodiment, the P-type epitaxial layer includes a step recess to further enhance the field spreading effect of the termination structure.

A high-electron-mobility field effect transistor is formed with a buffer region having a stepped lateral profile, the stepped lateral profile having first, second and third cross-sections of the buffer region, the first cross-section being thicker than the third cross-section and including a buried field plate, the second cross-section interposed between the first and third cross-sections and forming oblique angles with the first and third cross-sections. A barrier region is formed along the stepped lateral profile. The barrier region is separated from the buried field plate by a portion of the buffer region. The buffer region is formed from a first semiconductor material and the barrier region is formed from a second semiconductor material. The first and second semiconductor materials have different band-gaps such that an electrically conductive channel of a two-dimensional charge carrier gas arises at an interface between the buffer and barrier regions.

There is provided a method for manufacturing a structure, including:

applying a first etching to a surface of a member, at least the surface being composed of Group III nitride; and applying a second etching to the surface to which the first etching has been applied, wherein in applying the first etching, a flat portion and a protruding portion are formed, the flat portion being newly appeared on the surface by etching, and the protruding portion being raised with respect to the flat portion, which is caused by being less likely to be etched than the flat portion, and in applying the second etching, the protruding portion is lowered by etching the protruding portion.

Some embodiments of the disclosure provide a semiconductor device. The semiconductor device includes: a doped substrate; a barrier layer, disposed on the doped substrate; a channel layer, disposed between the doped substrate and the barrier layer; and a doped semiconductor structure, disposed in the doped substrate, where a band gap of the barrier layer is greater than a band gap of the channel layer, the doped substrate and the doped semiconductor structure have different polarities, and the doped substrate includes a doped silicon substrate.

A method for the reuse of gallium nitride (GaN) epitaxial substrates uses band-gap-selective photoelectrochemical (PEC) etching to remove one or more epitaxial layers from bulk or free-standing GaN substrates without damaging the substrate, allowing the substrate to be reused for further growth of additional epitaxial layers. The method facilitates a significant cost reduction in device production by permitting the reuse of expensive bulk or free-standing GaN substrates.

A bipolar transistor comprising a subcollector layer, and a collector layer on the subcollector layer. The collector layer includes a plurality of doped layers. The plurality of doped layers includes a first doped layer that has a highest impurity concentration thereamong and is on a side of or in contact with the subcollector layer. Also, the first doped layer includes a portion that extends beyond at least one edge of the plurality of doped layers in a cross-sectional view.

A semiconductor device provided with a substrate made of material except for semiconductors and having thermal conductivity greater than that of the semiconductor material. The semiconductor device provides, on the support, a metal layer, a primary mesa, and electrodes formed on the primary mesa. The metal layer, which is in contact with the primary mesa, may be made of at least one of tungsten (W), molybdenum (Mo), and tantalum (Ta) with a thickness of the 10 to 60 nm.

A field effect transistor according to the present invention includes a semiconductor layer including a groove, an insulating film formed on an upper surface of the semiconductor layer and having an opening above the groove and a gate electrode buried in the opening to be in contact with side surfaces and a bottom surface of the groove and having parts being in contact with an upper surface of the insulating film on both sides of the opening, wherein the gate electrode has a T-shaped sectional shape in which a width of an upper end is larger than a width of the upper surface of the insulating film.

A horizontal nanosheet field effect transistor (hNS FET) including source and drain electrodes, a gate electrode between the source and drain electrodes, a first spacer separating the source electrode from the gate electrode, a second spacer separating the drain electrode from the gate electrode, and a channel region under the gate electrode and extending between the source electrode and the drain electrode. The source electrode and the drain electrode each include an extension region. The extension region of the source electrode is under at least a portion of the first spacer and the extension region of the drain electrode is under at least a portion of the second spacer. The hNS FET also includes at least one layer of crystalline barrier material having a first thickness at the extension regions of the source and drain electrodes and a second thickness less than the first thickness at the channel region.