After forming a buried nanowire segment surrounded by a gate structure located on a substrate, an epitaxial source region is grown on a first end of the buried nanowire segment while covering a second end of the buried nanowire segment and the gate structure followed by growing an epitaxial drain region on the second end of the buried nanowire segment while covering the epitaxial source region and the gate structure. The epitaxial source region includes a first semiconductor material and dopants of a first conductivity type, while the epitaxial drain region includes a first semiconductor material different from the first semiconductor material and dopants of a second conductivity type opposite the first conductivity type.

A method of forming a MOSFET device is provided including: providing an SOI wafer; forming a dummy gate oxide and dummy gates on portions of the SOI layer that serve as channel regions of the device; forming spacers and doped source/drain regions in the SOI layer on opposite sides of the dummy gates; depositing a gap fill dielectric; removing the dummy gates/gate oxide; recessing areas of the SOI layer exposed by removal of the dummy gates forming one or more u-shaped grooves that extend part-way through the SOI layer such that a thickness of the SOI layer remaining in the channel regions is less than a thickness of the SOI layer in the doped source/drain regions under the spacers; and forming u-shaped replacement gate stacks in the u-shaped grooves such that u-shaped channels are formed in fully depleted regions of the SOI layer adjacent to the u-shaped replacement gate stacks.

Provided is a stabilizing circuit structure using a sense field effect transistor (sense-FET). A power semiconductor module includes a depletion-mode field effect transistor (D-mode FET) and the sense FET that has same structure as the D-mode FET and varies in area. Also the power semiconductor module includes not only an enhancement-mode field effect transistor (E-mode FET), but also the stabilizing circuit including circuit elements such as a resistor, a capacitor, an inductor, or a diode.

Provided is a semiconductor device including a DC/DC converter circuit, wherein the DC/DC converter circuit includes a transistor of a normally-off type, having a first drain electrode connected town input terminal and a first source electrode connected to an output terminal, which is formed in a first compound semiconductor substrate having a two-dimensional electron gas layer, and a transistor having a second drain electrode connected to the first source electrode and a grounded second source electrode.

Embodiments of the present invention provide an improved semiconductor structure and methods of fabrication that provide transistor contacts that are self-aligned in two dimensions. Two different capping layers are used, each being comprised of a different material. The two capping layers are selectively etchable to each other. One capping layer is used for gate coverage while the other capping layer is used for source/drain coverage. Selective etch processes open the desired gates and source/drains, while block masks are used to cover elements that are not part of the connection scheme. A metallization line (layer) is deposited, making contact with the open elements to provide electrical connectivity between them.

The characteristics of a semiconductor device are improved. A semiconductor device has a potential fixed layer containing a p type impurity, a channel layer, and a barrier layer, formed over a substrate, and a gate electrode arranged in a trench penetrating through the barrier layer, and reaching some point of the channel layer via a gate insulation film. Source and drain electrodes are formed on opposite sides of the gate electrode. The p type impurity-containing potential fixed layer has an inactivated region containing an inactivating element such as hydrogen between the gate and drain electrodes. Thus, while raising the p type impurity (acceptor) concentration of the potential fixed layer on the source electrode side, the p type impurity of the potential fixed layer is inactivated on the drain electrode side. This can improve the drain-side breakdown voltage while providing a removing effect of electric charges by the p type impurity.

According to an embodiment a semiconductor device includes a semiconductor body with a mesa section that may include a rectifying structure and a first drift zone section. The mesa section surrounds a field electrode structure that includes a field electrode and a field dielectric sandwiched between the field electrode and the semiconductor body. A maximum horizontal extension of the field electrode in a measure plane parallel to a first surface of the semiconductor body is at most 500 nm.

GaN-based half bridge power conversion circuits employ control, support and logic functions that are monolithically integrated on the same devices as the power transistors. In some embodiments a low side GaN device communicates through one or more level shift circuits with a high side GaN device. Both the high side and the low side devices may have one or more integrated control, support and logic functions. Some devices employ electro-static discharge circuits and features formed within the GaN-based devices to improve the reliability and performance of the half bridge power conversion circuits.

Methods and structures for improving the performance of integrated semiconductor transistors operating at high frequency and/or high power are described. Two capacitors may be connected to an input of a semiconductor transistor and tuned to suppress second-harmonic generation and to transform and match the input impedance of the device. A two-stage tuning procedure is described. The transistor may comprise gallium nitride and may be configured as a power transistor capable of handling up to 1000 W of power. A tuned transistor may operate at frequencies up to 6 GHz with a peak drain efficiency greater than 60%.

A high-voltage field effect transistor (HFET) includes a first semiconductor material, a second semiconductor material, and a heterojunction. The heterojunction is disposed between the first semiconductor material and the second semiconductor material. The HFET also includes a plurality of composite passivation layers, where a first composite passivation layer includes a first insulation layer and a first passivation layer, and a second composite passivation layer includes a second insulation layer and a second passivation layer. A gate dielectric is disposed between the first passivation layer and the second semiconductor material. A gate electrode is disposed between the gate dielectric and the first passivation layer. A first gate field plate is disposed between the first passivation layer and the second passivation layer. A source electrode and a drain electrode are coupled to the second semiconductor material, and a source field plate is coupled to the source electrode.