Abstract: Methods of fabricating halo regions are provided. In one aspect, a method is provided of fabricating a first halo region and a second halo region for a circuit device of a first conductivity type and having a gate structure with first and second sidewalls. The first halo region of a second conductivity type is formed by implanting the substrate with impurities in a first direction toward the first sidewall of the gate structure. The second halo region of the second conductivity type is formed by implanting the substrate with impurities in a second direction toward the second sidewall of the gate structure. The first and second halo regions are formed without implanting impurities in a direction substantially perpendicular to the first and second directions.

Abstract: In one illustrative embodiment, the method comprises providing an SOI substrate comprised of an active layer, a buried insulation layer and a bulk substrate, forming a doped region in the bulk substrate under the active layer, forming a plurality of transistors above the SOI substrate in an area above the doped region and applying a voltage to the doped region to vary a threshold voltage of at least one of the plurality of transistors.

Abstract: In one illustrative embodiment, the device comprises a transistor formed above a silicon-on-insulator substrate comprised of a bulk substrate, a buried insulation layer and an active layer, the bulk. substrate being doped with a first type of dopant material and a first well formed in the bulk substrate, the first well being doped with a second type of dopant material that is of a type opposite the first type of dopant material. The device further comprises a second well formed in the bulk substrate within the first well, the second well being doped with a dopant material that is the same type as the first type of dopant material, the transistor being formed in the active layer above the second well, an electrical contact for the first well and an electrical contact for said second well.

Abstract: In one illustrative embodiment, the method comprises forming a gate electrode above an SOI substrate comprised of a bulk substrate, a buried insulation layer and an active layer, the gate electrode having a protective layer formed thereabove, and forming a plurality of dielectric regions in the bulk substrate after the gate electrode is formed, the dielectric regions being self-aligned with respect to the gate electrode, the dielectric regions having a dielectric constant that is less than a dielectric constant of the bulk substrate.