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 method of manufacturing a semiconductor device that includes a junction field effect transistor, the junction field effect transistor including a semiconductor substrate of a first conductivity type, an epitaxial layer of the first conductivity type formed on the semiconductor substrate, a source region of the first conductivity type formed on a surface of the epitaxial layer, a channel region of the first conductivity type formed in a lower layer of the source region, a pair of trenches formed in the epitaxial layer so as to sandwich the source region therebetween, and a pair of gate regions of a second conductivity type, opposite to the first conductivity type, formed below a bottom of the pair of trenches.

A solid source-diffused junction is described for fin-based electronics. In one example, a fin is formed on a substrate. A glass of a first dopant type is deposited over the substrate and over a lower portion of the fin. A glass of a second dopant type is deposited over the substrate and the fin. The glass is annealed to drive the dopants into the fin and the substrate. The glass is removed and a first and a second contact are formed over the fin without contacting the lower portion of the fin.

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.

In order to secure the performance of a SiC-based JFET having an impurity diffusion rate lower than silicon-based one, a gate depth is secured while precisely controlling a distance between gate regions, instead of forming gate regions by ion implantation into the side wall of a trench. This means that a channel region defined by a gate distance and a gate depth should have a high aspect ratio. Further, due to limitations of process, a gate region is formed within a source region. Formation of a highly doped PN junction between source and gate regions causes various problems such as inevitable increase in junction current. In addition, a markedly high energy ion implantation becomes necessary for the formation of a termination structure. In the invention, provided is a vertical channel type SiC power JFET having a floating gate region below and separated from a source region and between gate regions.

A semiconductor device includes: a substrate; a first nitride semiconductor layer on the substrate; a second nitride semiconductor layer on the first nitride semiconductor layer; a drain contact and a source contact on the second nitride semiconductor layer; a common contact on the second nitride semiconductor layer and between the drain contact and source contact; a first gate structure on the second nitride semiconductor layer and between the drain contact and common contact; a second gate structure on the second nitride semiconductor layer and between the common contact and source contact; a conductive wire on the source contact; a dielectric layer on the second nitride semiconductor layer and covering a portion of a lateral surface of the conductive wire; and a conductive via connected to the conductive wire, extending through a portion of the dielectric layer, the second nitride semiconductor layer, and the first nitride semiconductor layer to the substrate.

Apparatus and circuits with dual threshold voltage transistors and methods of fabricating the same are disclosed. In one example, a semiconductor structure is disclosed. The semiconductor structure includes: a substrate; a first layer comprising a first III-V semiconductor material formed over the substrate; a first transistor formed over the first layer, and a second transistor formed over the first layer. The first transistor comprises a first gate structure comprising a first material, a first source region and a first drain region. The second transistor comprises a second gate structure comprising a second material, a second source region and a second drain region. The first material is different from the second material.

A device includes a p-well region, and a first High-Voltage N-type Well (HVNW) region and a second HVNW region contacting opposite edges of the p-well region. A P-type Buried Layer (PBL) has opposite edges in contact with the first HVNW region and the second HVNW region. An n-type buried well region is underlying the PBL. The p-well region and the n-type buried well region are in contact with a top surface and a bottom surface, respectively, of the PBL. The device further includes a n-well region in a top portion of the p-well region, an n-type source region in the n-well region, a gate stack overlapping a portion of the p-well region and a portion of the second HVNW region, and a channel region under the gate stack. The channel region interconnects the n-well region and the second HVNW region.

A nitride semiconductor device according to the present disclosure includes a substrate, a p-type GaN layer formed on a main surface of the substrate and made of Al.sub.xIn.sub.yGa.sub.1-x-yN containing p-type impurities, where 0X<1, 0Y<1, and a Ti film formed on the p-type GaN layer. The Ti film is in a coherent or metamorphic state with respect to the p-type GaN layer.

A dielectric and isolation lower fin material is described that is useful for fin-based electronics. In some examples, a dielectric layer is on first and second sidewalls of a lower fin. The dielectric layer has a first upper end portion laterally adjacent to the first sidewall of the lower fin and a second upper end portion laterally adjacent to the second sidewall of the lower fin. An isolation material is laterally adjacent to the dielectric layer directly on the first and second sidewalls of the lower fin and a gate electrode is over a top of and laterally adjacent to sidewalls of an upper fin. The gate electrode is over the first and second upper end portions of the dielectric layer and the isolation material.