A JFET having vertical and horizontal channel elements may be made from a semiconductor material such as silicon carbide using a first mask for multiple implantations to form a horizontal planar JFET region comprising a lower gate, a horizontal channel, and an upper gate, all above a drift region resting on a drain substrate region, such that the gates and horizontal channel are self-aligned with the same outer size and outer shape in plan view. A second mask may be used to create a vertical channel region abutting the horizontal channel region. The horizontal channel and vertical channel may each have multiple layers with varying doping concentrations. Angled implantations may use through the first mask to implant portions of the vertical channel regions. The window of the second mask may partially overlap the horizontal JFET region to insure abutment of the vertical and horizontal channel regions.

Trench JFETs may be created by etching trenches into the topside of a substrate of a first doping type to form mesas. The substrate is made up of a backside drain layer, a middle drift layer, and topside source layer. The etching goes through the source layer and partly into the drift layer. Gate regions are formed on the sides and bottoms of the trenches using doping of a second type. Vertical channel regions are formed behind the vertical gate segments via angled implantation using a doping of the first kind, providing improved threshold voltage control. Optionally the substrate may include a lightly doped channel layer between the drift and source layers, such that the mesas include a lightly doped channel region that more strongly contrasts with the implanted vertical channel regions.

A transient-voltage-suppression protection device and a manufacturing process therefor, and an electronic product. The transient-voltage-suppression protection device includes a substrate, a first trap, a second trap, a first injection region, and a second injection region, where the first trap and the second trap are sequentially arranged on the substrate from left to right at an interval, have a same doping type that is opposite to a doping type of the substrate, and are respectively provided with the first injection region and the second injection region with opposite doping types. The electronic product includes the transient-voltage-suppression protection device. In the solutions described, protection can be triggered and started at a lower voltage; the capacitance is small, and the manufacturing process is simple.

A semiconductor device includes a first gallium nitride layer disposed on a semiconductor substrate, and an aluminum gallium nitride layer disposed on the first gallium nitride layer. The semiconductor device also includes an upper recess and a lower recess disposed in the aluminum gallium nitride layer, wherein the upper recess adjoins the lower recess, and the upper recess has a width that is greater than that of the lower recess. The semiconductor device further includes a second gallium nitride layer disposed in the first recess and the second recess, and a gate structure disposed on the second gallium nitride layer. In addition, the semiconductor device includes a source electrode and a drain electrode disposed on the aluminum gallium nitride layer.

In a semiconductor switch with a monolithically integrated field effect transistor, the source or emitter region of the field effect transistor is connected via a semiconductor region and an n-doped contact region to a first electrical terminal. In the semiconductor region, a semiconductor structure with n-doped channels is formed between the n-doped contact region and the source or emitter region of the field effect transistor; the n-doped channels electrically connect the n-doped contact region with the source or emitter region of the field effect transistor and run between p-doped regions that are connected to the n-doped contact region. The semiconductor switch is suitable as a self-switching load disconnector and has low losses in the switched-on state.

A JFET transistor device having a reduced pitch may be manufactured using self-alignment techniques, while avoiding misalignments that may lead to decreased breakdown voltage and/or increased R.sub.DSon. Consequently, described devices provide, for a given active area and gate voltage, additional current channels, increased current, and reduced R.sub.DSon, as compared to conventional devices, while retaining high BV.sub.gs values.

A semiconductor device that is composed of an epitaxial semiconductor material stacked structure that includes a first epitaxial channel for a first junction field effect transistor (JFET) atop a supporting substrate and a second epitaxial channel region for a second junction field effect transistor (JFET). A commonly electrically contacted source/drain region for each of the first JFET and the second JFET is positioned at an interface of the first and second epitaxial channel region. A channel length for each of the first and second is substantially perpendicular to an upper surface of the supporting substrate. An epitaxial semiconductor gate conductor in direct contact with each of said first epitaxial channel region and the second epitaxial channel region.

A JFET is provided with a very low gate current. In tests the excess gate current above the theoretical minimum current for a similarly sized reverse biased p-n junction was not observed. The JFET includes a lightly doped top gate and doped regions beneath the drain of the JFET.

A vertical conduction junction transistor apparatus includes a multilayered semiconductor unit cell that has a substrate, epitaxial drift layer, epitaxial channel layer, gate region and channel control region. The substrate is silicon carbide (SiC). The epitaxial drift layer comprises SiC and is formed on the top surface of the substrate. The epitaxial channel layer comprises SiC and is formed on a top surface of the epitaxial drift layer, where a sidewall of the epitaxial channel layer is at an angle to the vertical direction. The gate region is formed in the sidewall of the epitaxial channel layer, the gate region having an inner gate region boundary that is parallel to the sidewall. The channel control region is in the epitaxial channel layer and has a width bounded by the inner gate region boundary. The channel control region has a trapezoidal cross-section in a plane taken in the vertical direction.

A semiconductor device that is composed of an epitaxial semiconductor material stacked structure that includes a first epitaxial channel for a first junction field effect transistor (JFET) atop a supporting substrate and a second epitaxial channel region for a second junction field effect transistor (JFET). A commonly electrically contacted source/drain region for each of the first JFET and the second JFET is positioned at an interface of the first and second epitaxial channel region. A channel length for each of the first and second is substantially perpendicular to an upper surface of the supporting substrate. An epitaxial semiconductor gate conductor in direct contact with each of said first epitaxial channel region and the second epitaxial channel region.