Semiconductor structures having a source contact and a drain contact that exhibit reduced contact resistance and methods of forming the same are disclosed. In one embodiment of the present application, the reduced contact resistance is provided by forming a layer of a dipole metal or metal-insulator-semiconductor (MIS) oxide between an epitaxial semiconductor material (providing the source region and the drain region of the device) and an overlying metal semiconductor alloy. In yet other embodiment, the reduced contact resistance is provided by increasing the area of the source region and drain region by patterning the epitaxial semiconductor material that constitutes at least an upper portion of the source region and drain region of the device.

A semiconductor device has a first semiconductor die and second semiconductor die with a conductive layer formed over the first semiconductor die and second semiconductor die. The second semiconductor die is disposed adjacent to the first semiconductor die with a side surface and the conductive layer of the first semiconductor die contacting a side surface and the conductive layer of the second semiconductor die. An interconnect, such as a conductive material, is formed across a junction between the conductive layers of the first and second semiconductor die. The conductive layer may extend down the side surface of the first semiconductor die and further down the side surface of the second semiconductor die. An extension of the side surface of the first semiconductor die can interlock with a recess of the side surface of the second semiconductor die. The conductive layer extends over the extension and into the recess.

A semiconductor device includes a first active structure on a substrate including a first epitaxial pattern, a second epitaxial pattern and a first channel pattern between the first epitaxial pattern and the second epitaxial pattern, the first channel pattern including at least one channel pattern stacked on the substrate. A first gate structure is disposed on top and bottom surfaces of the first channel pattern. A second active structure on the substrate and includes the second epitaxial pattern, a third epitaxial pattern and a second channel pattern between the second epitaxial pattern and the third epitaxial pattern in the first direction. The second channel pattern includes at least one channel pattern stacked on the substrate. The number of stacked second channel patterns is greater than the number of stacked first channel patterns. A second gate structure is disposed on top and bottom surfaces of the second channel pattern.

A semiconductor device structure is provided. The semiconductor device structure includes a semiconductor substrate and a first fin structure, a second fin structure, and a third fin structure over the semiconductor substrate. The semiconductor device structure also includes a merged semiconductor element on the first fin structure and the second fin structure and an isolated semiconductor element on the third fin structure. The semiconductor device structure further includes an isolation feature over the semiconductor substrate and partially or completely surrounding the first fin structure, the second fin structure, and the third fin structure. A top surface of the first fin structure is below a top surface of the isolation feature, and a top surface of the third fin structure is above the top surface of the isolation feature.

A method for forming spacers of a gate of a field effect transistor is provided, the gate including sides and a top and being located above a layer of a semiconductor material, the method including a step of forming a dielectric layer that covers the gate; after the step of forming the dielectric layer, at least one step of modifying the dielectric layer by ion implantation while retaining non-modified portions of the dielectric layer covering sides of the gate and being at least non-modified over their entire thickness; the ions having a hydrogen base and/or a helium base; at least one step of removing the modified dielectric layer using a selective etching of the dielectric layer, wherein the removing includes a wet etching with a base of a solution including hydrofluoric acid diluted to x % by weight, with x≦0.2, and having a pH less than or equal to 1.5.

Electrostatic discharge (ESD) protection is provided in circuits which use of a tunneling field effect transistor (TFET) or an impact ionization MOSFET (IMOS). These circuits are supported in silicon on insulator (SOI) and bulk substrate configurations to function as protection diodes, supply clamps, failsafe circuits and cutter cells. Implementations with parasitic bipolar devices provide additional parallel discharge paths.

Semiconductor devices are provided. The semiconductor devices may include a first wire pattern extending in a first direction on a substrate and a second wire pattern on the first wire pattern. The second wire pattern may be spaced apart from the first wire pattern and extends in the first direction. The semiconductor devices may also include a first gate structure at least partially surrounding the first wire pattern and the second wire pattern, a second gate structure spaced apart from the first gate structure in the first direction, a first source/drain region between the first gate structure and the second gate structure, a first spacer between a bottom surface of the first source/drain region and the substrate, a first source/drain contact on the first source/drain region, and a second spacer between the first source/drain contact and the first gate structure.

A semiconductor structure and a method for forming the semiconductor structure are provided. The semiconductor structure includes a substrate and a gate structure on the substrate. The substrate contains source-drain openings on both sides of the gate structure. The semiconductor structure also includes a first stress layer formed in a source-drain opening of the source-drain openings. The first stress layer is doped with first ions. In addition, the semiconductor structure includes a protection layer over the first stress layer, and an inversion layer between the first stress layer and the protection layer. The protection layer is doped with second ions, and the inversion layer is doped with third ions. A conductivity type of the third ions is opposite to a conductivity type of the second ions.

A semiconductor structure includes a substrate, first fins extending from the substrate with a first fin pitch, and second fins extending from the substrate with a second fin pitch smaller than the first fin pitch. The semiconductor structure also includes first gate structures engaging the first fins with a first gate pitch and second gate structures engaging the second fins with a second gate pitch smaller than the first gate pitch. The semiconductor structure also includes first epitaxial semiconductor features partially embedded in the first fins and adjacent the first gate structures and second epitaxial semiconductor features partially embedded in the second fins and adjacent the second gate structures. A bottom surface of the first epitaxial semiconductor features is lower than a bottom surface of the second epitaxial semiconductor features.

A method for fabricating a semiconductor structure includes providing a base structure including a substrate, a dielectric layer formed on the substrate, a plurality of first openings formed in the dielectric layer in a first transistor region, and a plurality of second openings formed in the dielectric layer in a second transistor region. The method also includes forming a first work function layer an the dielectric layer covering bottom and sidewall surfaces of the first and the second openings, forming a first sacrificial layer in each first opening and each second opening with a top surface lower than the top surface of the dielectric layer, removing a portion of the first work function layer exposed by the first sacrificial layer, removing the first work function layer formed in each first opening, and forming a second work function layer and a gate electrode in each first opening and each second opening.