Semiconductor devices and methods of fabricating such devices are provided. The devices include source and drain regions on one conductivity type separated by a channel length and a gate structure. The devices also include a channel region of the one conductivity type formed in the device region between the source and drain regions and a screening region of another conductivity type formed below the channel region and between the source and drain regions. In operation, the channel region forms, in response to a bias voltage at the gate structure, a surface depletion region below the gate structure, a buried depletion region at an interface of the channel region and the screening region, and a buried channel region between the surface depletion region and the buried depletion region, where the buried depletion region is substantially located in channel region.

An integrated circuit can include multiple SRAM cells, each including at least two pull-up transistors, at least two pull-down transistors, and at least two pass-gate transistors, each of the transistors having a gate; at least one of the pull-up transistors, the pull-down transistors, or the pass-gate transistors having a screening region a distance below the gate and separated from the gate by a semiconductor layer, the screening region having a concentration of screening region dopants, the concentration of screening region dopants being higher than a concentration of dopants in the semiconductor layer, the screening region providing an enhanced body coefficient for the pull-down transistors and the pass-gate transistors to increase the read static noise margin for the SRAM cell when a bias voltage is applied to the screening region; and a bias voltage network operable to apply one or more bias voltages to the multiple SRAM cells.

An integrated circuit die includes a substrate having a first layer of semiconductor material, a layer of dielectric material on the first layer of semiconductor material, and a second layer of semiconductor material on the layer of dielectric material. An extended channel region of a transistor is positioned in the second layer of semiconductor material, interacting with a top surface, side surfaces, and potentially portions of a bottom surface of the second layer of semiconductor material. A gate dielectric is positioned on a top surface and on the exposed side surface of the second layer of semiconductor material. A gate electrode is positioned on the top surface and the exposed side surface of the second layer of semiconductor material.

Semiconductor devices and methods of fabricating such devices are provided. The devices include source and drain regions on one conductivity type separated by a channel length and a gate structure. The devices also include a channel region of the one conductivity type formed in the device region between the source and drain regions and a screening region of another conductivity type formed below the channel region and between the source and drain regions. In operation, the channel region forms, in response to a bias voltage at the gate structure, a surface depletion region below the gate structure, a buried depletion region at an interface of the channel region and the screening region, and a buried channel region between the surface depletion region and the buried depletion region, where the buried depletion region is substantially located in channel region.

A semiconductor structure includes a bulk semiconductor substrate, an electrically insulating layer over the substrate, an active layer of semiconductor material over the electrically insulating layer and a transistor. The transistor includes an active region, a gate electrode region and an isolation junction region. The active region is provided in the active layer of semiconductor material and includes a source region, a channel region and a drain region. The gate electrode region is provided in the bulk semiconductor substrate and has a first type of doping. The isolation junction region is formed in the bulk semiconductor substrate and has a second type of doping opposite the first type of doping. The isolation junction region separates the gate electrode region from a portion of the bulk semiconductor substrate other than the gate electrode region that has the first type of doping.

A FET based double balanced mixer (DBM) that exhibits good conversion gain and IIP3 values and provides improved linearity and wide bandwidth. In one embodiment, a first balun is configured to receive a local oscillator (LO) signal and generate two balanced LO signals that are coupled to two corresponding opposing nodes of a four-node FET ring. A second balun is configured to pass an RF signal on the unbalanced side. The FET ring includes at least four FETs connected as branches of a ring, with the source of each FET connected to the drain of a next FET in the ring. Each FET is preferably fabricated as, or configured as, a low threshold voltage device having its gate connected to its drain, which causes the FET to operate as a diode, but with the unique characteristic of having close to a zero turn-on voltage.

An SOI wafer contains a compressively stressed buried insulator structure. In one example, the stressed buried insulator (BOX) may be formed on a host wafer by forming silicon oxide, silicon nitride and silicon oxide layers so that the silicon nitride layer is compressively stressed. Wafer bonding provides the surface silicon layer over the stressed insulator layer. Preferred implementations of the invention form MOS transistors by etching isolation trenches into a preferred SOI substrate having a stressed BOX structure to define transistor active areas on the surface of the SOI substrate. Most preferably the trenches are formed deep enough to penetrate through the stressed BOX structure and some distance into the underlying silicon portion of the substrate. The overlying silicon active regions will have tensile stress induced due to elastic edge relaxation.

New, distinct, and useful architectures for single-legged SOI-MOS were established and fabricated for the very first time. They incorporated into their architectures an innovative new configuration to wire the device Body to the Body-Tied-Source. This new configuration drastically increased the conductance between the Body and the Body-Tied-Source. This consequently allowed these devices to effectively support much higher operating biases. Same configuration also functioned on structures with very large peripheries. These gave proportional increase in this same conductivity, and for same area-efficiency, with the increase of their peripheries to accommodate higher currents. The functional model that governs this proportional scaling in these new architectures for single-legged SOI-MOS devices was established and is being claimed through this patent for the very first time. Through it, single-legged SOI-MOS devices will efficiently scale to area-efficient ultra large peripheries with minimal hits to their bandwidth.

A fully depleted field effect transistor (FET) and an anti-fuse structure are provided on a same chip. The fully depleted FET and the anti-fuse structure share a same high dielectric (k) constant dielectric material. The anti-fuse structure contains a faceted epitaxial doped semiconductor material as a bottom electrode, a high k dielectric material portion, and a gate electrode material portion as a top electrode. The sharp corners of the faceted epitaxial doped semiconductor material cause electric field concentration, which aid in the reduction of the breakdown voltage of the anti-fuse structure.

Methods and structures for forming a localized, strained region of a substrate are described. Trenches may be formed at boundaries of a localized region of a substrate. An upper portion of sidewalls at the localized region may be covered with a covering layer, and a lower portion of the sidewalls at the localized region may not be covered. A converting material may be formed in contact with the lower portion of the localized region, and the substrate heated. The heating may introduce a chemical species from the converting material into the lower portion, which creates stress in the localized region. The methods may be used to form strained-channel finFETs.