A method of fabricating a superconducting device includes determining a target transition temperature and utilizing a predefined quantitative relationship between superconducting transition temperature and an order parameter for at least one superconducting material composition is utilized to select a superconductor material composition that is capable of providing a target transition temperature. Process parameters may be controlled to form a superconductor device comprising at least one superconductor material having a material composition providing the target transition temperature.

A junction field effect transistor (JFET) includes a drift region disposed on a substrate that includes a drain region of the JFET. A lower gate region is disposed on the drift region, a source region is disposed above the lower gate region, and an upper gate region at least partially surrounding the source region and extending laterally beyond the lower gate region is disposed above the source region. The upper gate region extends laterally beyond the lower gate region by a distance defining a gate offset width between the upper gate region and the lower gate region.

The disclosed technology relates to semiconductors, and more particularly to a junction field effect transistor (JFET). In one aspect, a method of fabricating a JFET includes forming a well of a first dopant type in a substrate, wherein the well is isolated from the substrate by an isolation region of a second dopant type. The method additionally includes implanting a dopant of the second dopant type at a surface of the well to form a source, a drain and a channel of the JFET, and implanting a dopant of the first dopant type at the surface of the well to form a gate of the JFET. The method additionally includes, prior to implanting the dopant of the first type and the dopant of the second type, forming a pre-metal dielectric (PMD) layer on the well and forming contact openings in the PMD layer above the source, the drain and the gate. The PMD layer has a thickness such that the channel is formed by implanting the dopant of the first type and the dopant of the second type through the PMD layer. The method further includes, after implanting the dopant of the first type and the dopant of the second type, siliciding the source, the drain and the gate, and forming metal contacts in the contact openings.

A complementary metal oxide semiconductor (CMOS)-integrated junction field effect transistor (JFET) has reduced scale and reduced noise. An exemplary JFET has a substrate layer of one dopant type with a gate layer of that dopant type disposed on the substrate, a depletion channel of a second dopant type disposed on the first gate layer, and a second gate layer of the first dopant type disposed on the depletion channel and proximate a surface of the transistor. The second gate layer can separate the depletion channel from the surface, and the depletion channel separates the first gate layer from the second gate layer.

A device includes a buried well region and a first HVW region of the first conductivity, and an insulation region over the first HVW region. A drain region of the first conductivity type is disposed on a first side of the insulation region and in a top surface region of the first HVW region. A first well region and a second well region of a second conductivity type opposite the first conductivity type are on the second side of the insulation region. A second HVW region of the first conductivity type is disposed between the first and the second well regions, wherein the second HVW region is connected to the buried well region. A source region of the first conductivity type is in a top surface region of the second HVW region, wherein the source region, the drain region, and the buried well region form a JFET.

A method of forming a double-gated junction field effect transistors (JFET) and a tri-gated metal-oxide-semiconductor field effect transistor (MOSFET) on a common substrate is provided. The double-gated JFET is formed in a first region of a substrate by forming a semiconductor gate electrode contacting sidewall surfaces of a first channel region of a first semiconductor fin and a top surface of a portion of a first fin cap atop the first channel region. The tri-gated MOSFET is formed in a second region of the substrate by forming a metal gate stack contacting a top surface and sidewall surfaces of a second channel region of a second semiconductor fin.

In one embodiment, a method of forming a vertical transistor includes forming a layer comprising a semiconductor material above a substrate, defining three dimensional (3D) structures in the layer, forming a second region in at least one vertical sidewall of each 3D structure, and forming an isolation region between the 3D structures. In another embodiment, an apparatus includes at least one vertical transistor, where the at least one vertical transistor includes: a substrate comprising a semiconductor material, an array of 3D structures above the substrate, and an isolation region positioned between the 3D structures. Each 3D structure includes the semiconductor material. Each 3D structure also includes a first region having a first conductivity type and a second region having a second conductivity type, the second region including a portion of at least one vertical sidewall of the 3D structure.

A method of forming a double-gated junction field effect transistors (JFET) and a tri-gated metal-oxide-semiconductor field effect transistor (MOSFET) on a common substrate is provided. The double-gated JFET is formed in a first region of a substrate by forming a semiconductor gate electrode contacting sidewall surfaces of a first channel region of a first semiconductor fin and a top surface of a portion of a first fin cap atop the first channel region. The tri-gated MOSFET is formed in a second region of the substrate by forming a metal gate stack contacting a top surface and sidewall surfaces of a second channel region of a second semiconductor fin.

A nitride-based semiconductor device includes a first nitride-based semiconductor layer, a second nitride-based semiconductor layer, a gate electrode, a first source electrode, a second source electrode, and a drain electrode. The second nitride-based semiconductor layer includes a drift region doped, a first barrier region, and a second barrier region. The first and second barrier regions extend downward from a top surface of the second nitride-based semiconductor layer and are separated from each other by a portion of the drift region. The gate electrode is disposed on the first barrier region. The first source electrode is disposed on the portion of the drift region. The second source electrode is disposed on the second barrier region and is electrically coupled with the first source electrode. The drain electrode is connected to the first nitride-based semiconductor layer.

According to one embodiment, an apparatus includes a substrate, and at least one three dimensional (3D) structure above the substrate. The substrate and the 3D structure each include a semiconductor material. The 3D structure also includes: a first region having a first conductivity type, and a second region coupled to a portion of at least one vertical sidewall of the 3D structure.