Abstract: The present disclosure describes a semiconductor device having an asymmetric source/drain (S/D) design. The semiconductor device includes multiple semiconductor layers on a substrate, a gate structure wrapped around the multiple semiconductor layers, an inner spacer structure between the multiple semiconductor layers and in contact with a first side of the gate structure, and an epitaxial layer in contact with a second side of the gate structure. The second side is opposite to the first side.

Abstract: A semiconductor device according to the present disclosure includes a dielectric fin having a helmet layer, a gate structure disposed over a first portion of the helmet layer and extending along a direction, and a dielectric layer adjacent the gate structure and disposed over a second portion of the helmet layer. A width of the first portion along the direction is greater than a width of the second portion along the direction.

Abstract: Various embodiments of the present disclosure provide a semiconductor device structure. In one embodiment, the semiconductor device structure includes a source/drain feature over a substrate, a plurality of semiconductor layers over the substrate, a gate electrode layer surrounding a portion of each of the plurality of the semiconductor layers, a gate dielectric layer in contact with the gate electrode layer, and a cap layer. The cap layer has a first portion disposed between the plurality of semiconductor layers and the source/drain feature and a second portion extending outwardly from opposing ends of the first portion. The semiconductor device structure further includes a dielectric spacer disposed between and in contact with the source/drain feature and the second portion of the cap layer.

Abstract: Multi-gate devices and methods for fabricating such are disclosed herein. An exemplary device includes a channel layer, a first source/drain feature, a second source/drain feature, and a metal gate. The channel layer has a first horizontal segment, a second horizontal segment, and a vertical segment connects the first horizontal segment and the second horizontal segment. The first horizontal segment and the second horizontal segment extend along a first direction, and the vertical segment extends along a second direction. The vertical segment has a width along the first direction and a thickness along the second direction, and the thickness is greater than the width. The channel layer extends between the first source/drain feature and the second source/drain feature along a third direction. The metal gate wraps channel layer. In some embodiments, the first horizontal segment and the second horizontal segment are nanosheets.

Abstract: A method of manufacturing a semiconductor device, a plurality of fin structures are formed over a semiconductor substrate. The fin structures extend along a first direction and are arranged in a second direction crossing the first direction. A plurality of sacrificial gate structures extending in the second direction are formed over the fin structures. An interlayer dielectric layer is formed over the plurality of fin structures between adjacent sacrificial gate structures. The sacrificial gate structures are cut into a plurality of pieces of sacrificial gate structures by forming gate end spaces along the second direction. Gate separation plugs are formed by filling the gate end spaces with two or more dielectric materials. The two or more dielectric materials includes a first layer and a second layer formed on the first layer, and a dielectric constant of the second layer is smaller than a dielectric constant of the first layer.

Abstract: A semiconductor device according to the present disclosure includes a dielectric fin having a helmet layer, a gate structure disposed over a first portion of the helmet layer and extending along a direction, and a dielectric layer adjacent the gate structure and disposed over a second portion of the helmet layer. A width of the first portion along the direction is greater than a width of the second portion along the direction.

Abstract: A semiconductor device structure includes a dielectric layer, a first source/drain feature in contact with the dielectric layer, wherein the first source/drain feature comprises a first sidewall. The structure also includes a second source/drain feature in contact with the dielectric layer and adjacent to the first source/drain feature, wherein the second source/drain feature comprises a second sidewall. The structure also includes an insulating layer disposed over the dielectric layer and between the first sidewall and the second sidewall, wherein the insulating layer comprises a first surface facing the first sidewall, a second surface facing the second sidewall, a third surface connecting the first surface and the second surface, and a fourth surface opposite the third surface. The structure further includes a sealing material disposed between the first sidewall and the first surface, wherein the sealing material, the first sidewall, the first surface, and the dielectric layer are exposed to an air gap.

Abstract: A semiconductor device structure, along with methods of forming such, are described. In one embodiment, a semiconductor device structure is provided. The semiconductor device structure includes a substrate having a front side and a back side opposing the front side, a gate stack disposed on the front side of the substrate, and a first source/drain feature and a second source/drain feature disposed in opposing sides of the gate stack. Each first source/drain feature and second source/drain feature comprises a first side and a second side, and a portion of the back side of the substrate is exposed to an air gap.

Abstract: Embodiments of the present disclosure includes a semiconductor device. The semiconductor device includes first suspended nanostructures vertically stacked over one another and disposed on a substrate, a first gate stack engaging the first suspended nanostructures, a first gate spacer disposed on sidewalls of the first gate stack, second suspended nanostructures vertically stacked over one another and disposed on the substrate, a second gate stack engaging the second suspended nanostructures, and a second gate spacer disposed on sidewalls of the second gate stack. A middle portion of the first suspended nanostructures has a first thickness measured in a direction perpendicular to a top surface of the substrate. A middle portion of the second suspended nanostructures has a second thickness measured in the direction. The second thickness is smaller than the first thickness.

Abstract: A semiconductor device structure includes a dielectric layer, a first source/drain feature in contact with the dielectric layer, wherein the first source/drain feature comprises a first sidewall, and a second source/drain feature in contact with the dielectric layer and adjacent to the first source/drain feature, wherein the second source/drain feature comprises a second sidewall. The structure also includes an insulating layer disposed over the dielectric layer and between the first sidewall and the second sidewall, wherein the insulating layer comprises a first surface facing the first sidewall, a second surface facing the second sidewall, a third surface connecting the first surface and the second surface, and a fourth surface opposite the third surface. The structure includes a sealing material disposed between the first sidewall and the first surface, wherein the sealing material, the first sidewall, the first surface, and the dielectric layer are exposed to an air gap.

Abstract: A method of manufacturing a semiconductor device, a plurality of fin structures are formed over a semiconductor substrate. The fin structures extend along a first direction and are arranged in a second direction crossing the first direction. A plurality of sacrificial gate structures extending in the second direction are formed over the fin structures. An interlayer dielectric layer is formed over the plurality of fin structures between adjacent sacrificial gate structures. The sacrificial gate structures are cut into a plurality of pieces of sacrificial gate structures by forming gate end spaces along the second direction. Gate separation plugs are formed by filling the gate end spaces with two or more dielectric materials. The two or more dielectric materials includes a first layer and a second layer formed on the first layer, and a dielectric constant of the second layer is smaller than a dielectric constant of the first layer.

Abstract: Multi-gate devices and methods for fabricating such are disclosed herein. An exemplary device includes a channel layer, a first source/drain feature, a second source/drain feature, and a metal gate. The channel layer has a first horizontal segment, a second horizontal segment, and a vertical segment connects the first horizontal segment and the second horizontal segment. The first horizontal segment and the second horizontal segment extend along a first direction, and the vertical segment extends along a second direction. The vertical segment has a width along the first direction and a thickness along the second direction, and the thickness is greater than the width. The channel layer extends between the first source/drain feature and the second source/drain feature along a third direction. The metal gate wraps channel layer. In some embodiments, the first horizontal segment and the second horizontal segment are nanosheets.

Abstract: A semiconductor device structure, along with methods of forming such, are described. In one embodiment, a semiconductor device structure is provided. The semiconductor device structure a first source/drain region, a second source/drain region, and a gate stack disposed between the first source/drain region and the second source/drain region. The semiconductor device structure also includes a conductive feature disposed below the first source/drain region. The semiconductor device structure also includes a power rail disposed below and in contact with the conductive feature. semiconductor device structure also includes a dielectric layer enclosing the conductive feature, wherein an air gap is formed between the dielectric layer and the conductive feature.

Abstract: A semiconductor device structure includes a dielectric layer, a first source/drain feature in contact with the dielectric layer, wherein the first source/drain feature comprises a first sidewall, and a second source/drain feature in contact with the dielectric layer and adjacent to the first source/drain feature, wherein the second source/drain feature comprises a second sidewall. The structure also includes an insulating layer disposed over the dielectric layer and between the first sidewall and the second sidewall, wherein the insulating layer comprises a first surface facing the first sidewall, a second surface facing the second sidewall, a third surface connecting the first surface and the second surface, and a fourth surface opposite the third surface. The structure includes a sealing material disposed between the first sidewall and the first surface, wherein the sealing material, the first sidewall, the first surface, and the dielectric layer are exposed to an air gap.

Abstract: Embodiments of the present disclosure includes a method of forming a semiconductor device. The method includes providing a substrate having a plurality of first semiconductor layers and a plurality of second semiconductor layers disposed over the substrate. The method also includes patterning the first semiconductor layers and the second semiconductor layers to form a first fin and a second fin, removing the first semiconductor layers from the first and second fins such that a first portion of the patterned second semiconductor layers becomes first suspended nanostructures in the first fin and that a second portion of the patterned second semiconductor layers becomes second suspended nanostructures in the second fin, and doping a threshold modifying impurity into the first suspended nanostructures in the first fin.

Abstract: Embodiments relate to a semiconductor device structure including a first channel layer having a first surface and a second surface, a second channel layer having a first surface and a second surface, and the first and second channel layers are formed of a first material. The structure also includes a first dopant suppression layer in contact with the second surface of the first channel layer, and a second dopant suppression layer parallel to the first dopant suppression layer. The second dopant suppression layer is in contact with the first surface of the second channel layer, and the first and second dopant suppression layers each comprises carbon or fluorine. The structure further includes a gate dielectric layer in contact with the first and second dopant suppression layers and the first surface of the first channel layer, and a gate electrode layer disposed on the gate dielectric layer.

Abstract: Embodiments relate to a semiconductor device structure including a first channel layer having a first surface and a second surface, a second channel layer having a first surface and a second surface, and the first and second channel layers are formed of a first material. The structure also includes a first dopant suppression layer in contact with the second surface of the first channel layer, and a second dopant suppression layer parallel to the first dopant suppression layer. The second dopant suppression layer is in contact with the first surface of the second channel layer, and the first and second dopant suppression layers each comprises carbon or fluorine. The structure further includes a gate dielectric layer in contact with the first and second dopant suppression layers and the first surface of the first channel layer, and a gate electrode layer disposed on the gate dielectric layer.

Abstract: A method includes receiving a semiconductor substrate. The semiconductor substrate has a top surface and includes a semiconductor element. Moreover, the semiconductor substrate has a fin structure formed thereon. The method also includes recessing the fin structure to form source/drain trenches, forming a first dielectric layer over the recessed fin structure in the source/drain trenches, implanting a dopant element into a portion of the fin structure beneath a bottom surface of the source/drain trenches to form an amorphous semiconductor layer, forming a second dielectric layer over the recessed fin structure in the source/drain trenches, annealing the semiconductor substrate, and removing the first and second dielectric layers. After the annealing and the removing steps, the method further includes further recessing the recessed fin structure to provide a top surface. Additionally, the method includes forming an epitaxial layer from and on the top surface.

Abstract: A semiconductor device includes first nanostructures vertically separated from one another, a first gate structure wrapping around each of the first nanostructures, and second nanostructures vertically separated from one another. The semiconductor device also includes a second gate structure wrapping around the second nanostructures, a first drain/source structure coupled to a first end of the first nanostructures, a second drain/source structure coupled to both of a second end of the first nanostructures and a first end of the second nanostructures, and a third drain/source structure coupled to a second end of the second nanostructures. The first drain/source structure has a first doping type, the second and third drain/source structures have a second doping type, and the first doping type is opposite to the second doping type.

Abstract: A semiconductor device structure, along with methods of forming such, are described. In one embodiment, a semiconductor device structure is provided. The semiconductor device structure a first source/drain region, a second source/drain region, and a gate stack disposed between the first source/drain region and the second source/drain region. The semiconductor device structure also includes a conductive feature disposed below the first source/drain region. The semiconductor device structure also includes a power rail disposed below and in contact with the conductive feature. semiconductor device structure also includes a dielectric layer enclosing the conductive feature, wherein an air gap is formed between the dielectric layer and the conductive feature.