A novel semiconductor transistor is presented. The semiconductor structure has a MOSFET like structure, with the difference that the device channel is formed in an intrinsic region, so as to effectively decrease the impurity and surface scattering phenomena deriving from a high doping profile typical of conventional MOS devices. Due to the presence of the un-doped channel region, the proposed structure greatly reduces Random Doping Fluctuation (RDF) phenomena decreasing the threshold voltage variation between different devices. In order to control the threshold voltage of the device, a heavily doped poly-silicon or metallic gate is used. However, differently from standard CMOS devices, a high work-function metallic material, or a heavily p-doped poly-silicon layer, is used for an n-channel device and a low work-function metallic material, or heavily n-doped poly-silicon layer, is used for a p-channel FET. Doped or insulating regions are used to increase the control on the channel conductivity.

Disclosed are a structure for improving electrical signal isolation in a semiconductor substrate and an associated method for the structure's fabrication. The structure includes a deep trench having sidewalls disposed in the semiconductor substrate. An isolation region may be formed along at least an upper portion of the sidewalls of the deep trench, and a metallic filler may be disposed in the deep trench. The isolation region may include a PN junction formed by one or more of ion implantation and annealing, deposition of highly doped polysilicon and out diffusion, and gas phase doping and annealing. In the alternative, the isolation region may be a dielectric isolation region formed by one or more of uniform dielectric deposition, partial dieletric deposition, and dielectric deposition by ionic reaction.

A semiconductor device has an n-type buried layer formed by implanting antimony and/or arsenic into the p-type first epitaxial layer at a high dose and low energy, and implanting phosphorus at a low dose and high energy. A thermal drive process diffuses and activates both the heavy dopants and the phosphorus. The antimony and arsenic do not diffuse significantly, maintaining a narrow profile for a main layer of the buried layer. The phosphorus diffuses to provide a lightly-doped layer several microns thick below the main layer. An epitaxial p-type layer is grown over the buried layer.

One illustrative method disclosed includes, among other things, forming a vertically oriented semiconductor structure above a doped well region defined in a semiconductor substrate, the semiconductor structure comprising a lower source/drain region and an upper source/drain region, wherein the lower source/drain region physically contacts the upper surface of the substrate, forming a counter-doped isolation region in the substrate, forming a metal silicide region in the substrate above the counter-doped isolation region, wherein the metal silicide region is in physical contact with the lower source/drain region, and forming a lower source/drain contact structure that is conductively coupled to the metal silicide region.

An integrated circuit uses a compact CMOS device isolation scheme which forms a ring of N-well housing PMOS devices to encircle the P-well housing NMOS devices in a circuit block. An N-type buried layer is formed under the P-well and extends partially under the surrounding N-well. The compact CMOS device isolation scheme eliminates the use of a deep N-well ring around the circuit block. Therefore, the circuit blocks of the integrated circuit can be formed with reduced silicon area and the die size for implementing the integrated circuit is reduced.

A heterojunction semiconductor device with a low on-resistance includes a metal drain electrode, a substrate, and a buffer layer. A current blocking layer is arranged in the buffer layer, a gate structure is arranged on the buffer layer, and the gate structure comprises a metal gate electrode, GaN pillars and AlGaN layers, wherein a metal source electrode is arranged above the metal gate electrode; and the current blocking layer comprises multiple levels of current blocking layers, the centers of symmetry of the layers are collinear, and annular inner openings of the current blocking layers at all levels gradually become smaller from top to bottom. The AlGaN layers and the GaN pillars are distributed in a honeycomb above the buffer layer.

A semiconductor device with a substrate, a low defect layer formed in a fixed position relative to the substrate, and a barrier layer comprising III-N semiconductor material formed on the low-defect layer and forming an electron gas in the low-defect layer. The device also has a source contact, a drain contact, and a gate contact for receiving a potential, the potential for adjusting a conductive path in the electron gas and between the source contact and the drain contact. Lastly, the device has a one-sided PN junction between the barrier layer and the substrate.

Radiation hardened NMOS devices suitable for application in NMOS, CMOS, or BiCMOS integrated circuits, and methods for fabricating them. A device includes a p-type silicon substrate, a field oxide surrounding a moat region on the substrate tapering through a Bird's Beak region to a gate oxide within the moat region, a heavily-doped p-type guard region underlying at least a portion of the Bird's Beak region and terminating at the inner edge of the Bird's Beak region, a gate included in the moat region, and n-type source and drain regions spaced by a gap from the inner edge of the Bird's Beak and guard regions. A variation of minor alterations to the conventional moat and n-type source/drain masks. The resulting devices have improved radiation tolerance while having a high breakdown voltage and minimal impact on circuit density.

A semiconductor integrated circuit includes a semiconductor layer of a first conductivity type which is stacked on a support substrate with an insulating layer interposed between the semiconductor layer and the supp ort substrate, a first well region of a second conductivity type buried in an upper part of the semiconductor layer so as to be separated from the insulating layer, a second well region of the first conductivity type buried in an upper part of the first well region, and an isolation region of the first conductivity type buried in the upper part of the semiconductor layer such that the isolation region surrounds the first well region and is separated from the first well region and the insulating layer.

Aspects of the present disclosure provides a device comprising a P-type semiconductor substrate, an N-type tub above the semiconductor substrate, a P-type region provided in the N-type tub isolated by one or more P-type isolation structures, and an N-type punch-through stopper provided under the P-type regions isolated by the isolation structure(s). The punch-through stopper is heavily doped compared to the N-type tub. The P-type region has a width between the two isolation structures that is equal to or less than that of the N-type punch-through stopper.