There are disclosed herein various implementations of a III-Nitride bidirectional device. Such a bidirectional device includes a substrate, a back channel layer situated over the substrate, and a device channel layer and a device barrier layer situated over the back channel layer. The device channel layer and the device barrier layer are configured to produce a device two-dimensional electron gas (2DEG). In addition, the III-Nitride bidirectional device includes first and second gates formed on respective first and second depletion segments situated over the device barrier layer. The III-Nitride bidirectional device also includes a back barrier situated between the back channel layer and the device channel layer. A polarization of the back channel layer of the III-Nitride bidirectional device is substantially equal to a polarization of the device channel layer.

A silicon carbide substrate has first to third semiconductor layers. The first and third semiconductor layers have a first conductivity type, and the second semiconductor layer has a second conductivity type. A trench has a bottom surface and first to third side surfaces, the bottom surface being constituted of the first semiconductor layer, the first to third side surfaces being respectively constituted of the first to third semiconductor layers. A gate insulating film having a bottom portion and a side wall portion is provided on the trench. The bottom portion has a minimum thickness d.sub.0. A portion of the side wall portion on the second side surface has a minimum thickness d.sub.1. A portion, connected to the bottom portion, of the side wall portion on the first side surface has a thickness d.sub.2. Moreover, d.sub.2>d.sub.1 and d.sub.2>d.sub.0 are satisfied.

A semiconductor device includes a GaN FET with an overvoltage clamping component electrically coupled to a drain node of the GaN FET and coupled in series to a voltage dropping component. The voltage dropping component is electrically coupled to a terminal which provides an off-state bias for the GaN FET. The overvoltage clamping component conducts insignificant current when a voltage at the drain node of the GaN FET is less than the breakdown voltage of the GaN FET and conducts significant current when the voltage rises above a safe voltage limit. The voltage dropping component is configured to provide a voltage drop which increases as current from the overvoltage clamping component increases. The semiconductor device is configured to turn on the GaN FET when the voltage drop across the voltage dropping component reaches a threshold value.

A method for forming a high electron mobility transistor (HEMT) device with a plurality of alternating layers of one or more undoped gallium nitride (GaN) layers and one or more carbon doped gallium nitride layers (c-GaN), and an HEMT device formed by the method is disclosed. In one embodiment, the method includes forming a channel layer stack on a substrate, the channel layer stack having a plurality of alternating layers of one or more undoped gallium nitride (GaN) layers and one or more carbon doped gallium nitride layers (c-GaN). The method further includes forming a barrier layer on the channel layer stack. In one embodiment, the channel layer stack is formed by growing each of the one or more undoped gallium nitride (GaN) layers in growth conditions that suppress the incorporation of carbon in gallium nitride, and growing each of the one or more carbon doped gallium nitride (c-GaN) layers in growth conditions that promote the incorporation of carbon in gallium nitride.

A heterostructure field effect transistor (HFET) gallium nitride (GaN) semiconductor power device comprises a hetero-junction structure comprises a first semiconductor layer interfacing a second semiconductor layer of two different band gaps thus generating an interface layer as a two-dimensional electron gas (2DEG) layer. The power device further comprises a source electrode and a drain electrode disposed on two opposite sides of a gate electrode disposed on top of the hetero-junction structure for controlling a current flow between the source and drain electrodes in the 2DEG layer. The power device further includes a floating gate located between the gate electrode and hetero-junction structure, wherein the gate electrode is insulated from the floating gate with an insulation layer and wherein the floating gate is disposed above and padded with a thin insulation layer from the hetero-junction structure and wherein the floating gate is charged for continuously applying a voltage to the 2DEG layer to pinch off the current flowing in the 2DEG layer between the source and drain electrodes whereby the HFET semiconductor power device is a normally off device.

As a technique for attaining a reduction in power consumption, there is a technique for reducing power consumption using a spin wave. No specific proposal concerning spin wave generation, spin wave detection, and a latch technique for information has been made. A device applies an electric field to a first electrode of a nonmagnetic material using a thin line-shaped stacked body including a first ferromagnetic layer and a nonmagnetic layer to thereby generate a spin wave in the first ferromagnetic layer, and detects a phase or amplitude of the spin wave propagated in the first ferromagnetic layer using a second electrode of a ferromagnetic material with a magnetoresistance effect.

A technique relates to a semiconductor device. First metal contacts are formed on top of a substrate. The first metal contacts are arranged in a first direction, and the first metal contacts are arranged such that areas of the substrate remain exposed. Insulator pads are positioned at predefined locations on top of the first metal contacts, such that the insulator pads are spaced from one another. Second metal contacts are formed on top of the insulator pads, such that the second metal contacts are arranged in a second direction different from the first direction. The first and second metal contacts sandwich the insulator pads at the predefined locations. Surface-sensitive conductive channels are formed to contact the first metal contacts and the second metal contacts. Four-terminal devices are defined by the surface-sensitive conductive channels contacting a pair of the first metal contacts and contacting a pair of the metal contacts.

Provided are a group 13 nitride composite substrate allowing for the production of a semiconductor device suitable for high-frequency applications while including a conductive GaN substrate, and a semiconductor device produced using this substrate. The group 13 nitride composite substrate includes a base material of an n-conductivity type formed of GaN, a base layer located on the base material, being a group 13 nitride layer having a resistivity of 110.sup.6 .Math.cm or more, a channel layer located on the base layer, being a GaN layer having a total impurity density of 110.sup.17/cm.sup.3 or less, and a barrier layer that is located on the channel layer and is formed of a group 13 nitride having a composition Al.sub.xIn.sub.yGa.sub.1-x-yN (0x1, 0y1).

Methods for passivating a nanotube fabric layer within a nanotube switching device to prevent or otherwise limit the encroachment of an adjacent material layer are disclosed. In some embodiments, a sacrificial material is implanted within a porous nanotube fabric layer to fill in the voids within the porous nanotube fabric layer while one or more other material layers are applied adjacent to the nanotube fabric layer. Once the other material layers are in place, the sacrificial material is removed. In other embodiments, a non-sacrificial filler material (selected and deposited in such a way as to not impair the switching function of the nanotube fabric layer) is used to form a barrier layer within a nanotube fabric layer. In other embodiments, individual nanotube elements are combined with and nanoscopic particles to limit the porosity of a nanotube fabric layer.

III-nitride materials are generally described herein, including material structures comprising III-nitride material regions and silicon-containing substrates. Certain embodiments are related to gallium nitride materials and material structures comprising gallium nitride material regions and silicon-containing substrates.