Abstract: Semiconductor devices and methods are provided. An exemplary method according to the present disclosure includes providing fin-shaped active regions protruding from a substrate, forming cladding layers extending along sidewalls of the fin-shaped active regions, forming a dielectric feature over the substrate to fill space between two adjacent cladding layers, forming a gate structure over channel regions of the fin-shaped active regions and over a first portion of the cladding layers, performing an etching process to remove a second portion of the cladding layers not covered by the gate structure to form sidewall spacer trenches, forming a dielectric spacer in each of the sidewall spacer trenches, and after the forming of the dielectric spacers, forming source/drain features.

Abstract: A semiconductor device includes a substrate, two source/drain features disposed on the substrate, a stack of channel layers disposed over the substrate and between the two source/drain features, and a gate structure disposed over and wrapping around the stack of channel layers. Each channel layer of the stack of channel layers has a dog-bone shape in a cross-sectional view including the two source/drain features and the stack of channel layers. The gate structure includes a seam.

Abstract: A semiconductor structure includes a substrate, an oxide layer disposed over the substrate, a stack of semiconductor layers disposed over the oxide layer, and an epitaxial source/drain (S/D) feature disposed adjacent to the stack of semiconductor layers. A portion of the epitaxial S/D feature is horizontally surrounded by the oxide layer.

Abstract: A method includes performing a first etching process on a backside of a substrate to expose a dummy contact structure, performing a first deposition process to deposit a first portion of an oxide layer around the dummy contact structure, performing a second etching process to at least partially remove the first portion of oxide layer, forming a spacer layer around the dummy contact structure, performing a second deposition process to form a second portion of the oxide layer around the spacer layer, removing the spacer layer and the dummy contract structure to leave an opening, and filling the opening with a conductive material to form a conductive plug.

Abstract: A semiconductor structure includes a substrate including a dielectric layer over a semiconductor layer and an active region protruding from the dielectric layer. The active region includes a stack of semiconductor layers. The semiconductor structure further includes a metal gate structure disposed over the active region and interleaved with the stack of semiconductor layers, an isolation structure over the dielectric layer and covering sidewalls of a bottommost semiconductor layer, and an epitaxial source/drain (S/D) feature disposed adjacent to the metal gate structure. A bottom surface of the epitaxial S/D feature is defined by the bottommost semiconductor layer, and a portion of the bottommost semiconductor layer under the epitaxial S/D feature has a thickness less than a thickness of the dielectric layer.

Abstract: A method includes providing a semiconductor structure including a device fin protruding from a substrate, forming a dummy gate stack over the device fin, forming a first spacer over the device fin and the dummy gate stack, forming a second spacer over the first spacer, forming a dielectric feature adjacent to the second spacer, and replacing the dummy gate stack with a metal gate stack. Thereafter, the method removes the second spacer, thereby forming an air gap between the first spacer and the dielectric feature and wrapping around the device fin. The method then forms a sealing layer over the first spacer and the dielectric feature, thereby sealing the air gap.

Abstract: A semiconductor device with different gate structure configurations and a method of fabricating the semiconductor device are disclosed. The method includes depositing a high-K dielectric layer surrounding nanostructured channel regions, performing a first doping with a rare-earth metal (REM)-based dopant on first and second portions of the high-K dielectric layer, and performing a second doping with the REM-based dopants on the first portions of the high-K dielectric layer and third portions of the high-K dielectric layer. The first doping dopes the first and second portions of the high-K dielectric layer with a first REM-based dopant concentration. The second doping dopes the first and third portions of the high-K dielectric layer with a second REM-based dopant concentration different from the first REM-based dopant concentration.

Abstract: Semiconductor device and the manufacturing method thereof are disclosed. An exemplary semiconductor device comprises a semiconductor stack including semiconductor layers over a substrate, wherein the semiconductor layers are separated from each other and are stacked up along a direction substantially perpendicular to a top surface of the substrate; an isolation structure around a bottom portion of the semiconductor stack and separating active regions; a metal gate structure over a channel region of the semiconductor stack and wrapping each of the semiconductor layers; a gate spacer over a source/drain (S/D) region of the semiconductor stack and along sidewalls of a top portion of the metal gate structure; and an inner spacer over the S/D region of the semiconductor stack and along sidewalls of lower portions of the metal gate structure and wrapping edge portions of each of the semiconductor layers.

Abstract: Multi-gate devices and methods for fabricating such are disclosed herein. An exemplary method includes forming a diffusion blocking layer on a semiconductor substrate; forming channel material layers over the diffusion blocking layer; patterning the semiconductor substrate, the channel material layers, and the diffusion blocking layer to form a trench in the semiconductor substrate, thereby defining an active region being adjacent the trench; filling the trench with a dielectric material layer and a solid doping source material layer containing a dopant; and driving the dopant from the solid doping source material layer to the active region, thereby forming an anti-punch-through (APT) feature in the active region.

Abstract: A method includes providing a substrate, an isolation structure, and a fin extending from the substrate and through the isolation structure. The fin includes a stack of layers having first and second layers that are alternately stacked and have first and second semiconductor materials respectively. A topmost layer of the stack is one of the second layers. The structure further has a sacrificial gate stack engaging a channel region of the fin. The method further includes forming gate spacers and forming sidewall spacers on sidewalls of the fin in a source/drain region of the fin, wherein the sidewall spacers extend above a bottom surface of a topmost one of the first layers. The method further includes etching the fin in the source/drain region, resulting in a source/drain trench; partially recessing the second layers exposed in the source/drain trench, resulting in gaps; and forming dielectric inner spacers inside the gaps.

Abstract: The present disclosure provides a semiconductor device and a method of forming the same. A method according one embodiment of the present disclosure include bonding a first semiconductor substrate having (110) orientation on a second semiconductor substate having (100) orientation, forming a stack over the first semiconductor substrate, the stack comprising a plurality of channel layers interleaved by a plurality of sacrificial layers, patterning the stack to form a fin-shape structure, the fin-shape structure comprising a channel region and a source/drain region, recessing the source/drain region to form a source/drain trench, forming a dielectric film in the source/drain trench, and epitaxially growing an epitaxial feature over the dielectric film, the epitaxial feature being in contact with the plurality of channel layers. The epitaxial feature has (110) orientation.

Abstract: A method includes providing a substrate including a first semiconductor layer over a dielectric layer, thinning the first semiconductor layer, forming a stack of alternating second semiconductor layers and third semiconductor layers over the thinned first semiconductor layer, forming a fin active region protruding from the substrate including a portion of the thinned first semiconductor layer and the stack of alternating second semiconductor layers and third semiconductor layers, forming isolation features over an exposed portion of the dielectric layer, forming a dummy gate stack over the fin active region, forming a source/drain (S/D) recess in the fin active region adjacent to the dummy gate stack, forming an epitaxial S/D feature in the S/D recess, removing the second semiconductor layers to form openings between the third semiconductor layers, and forming a metal gate stack in the openings and in place of the dummy gate stack.

Abstract: A semiconductor device with different gate structure configurations and a method of fabricating the semiconductor device are disclosed. The method includes depositing a high-K dielectric layer surrounding nanostructured channel regions, performing a first doping with a rare-earth metal (REM)-based dopant on first and second portions of the high-K dielectric layer, and performing a second doping with the REM-based dopants on the first portions of the high-K dielectric layer and third portions of the high-K dielectric layer. The first doping dopes the first and second portions of the high-K dielectric layer with a first REM-based dopant concentration. The second doping dopes the first and third portions of the high-K dielectric layer with a second REM-based dopant concentration different from the first REM-based dopant concentration.

Abstract: A semiconductor structure and a method of forming the same are provided. In an embodiment, an exemplary method includes providing a workpiece having a first active region and a second active region protruding from a substrate, lined by cladding layers, and spaced by a first trench. The method also includes forming a dielectric layer over the workpiece to substantially fill the first trench, forming a mask film directly on a portion of the dielectric layer in the first trench after the forming of the dielectric layer, selectively recessing the dielectric layer after the forming of the mask film to form a dummy fin in and protruding from the first trench, performing an etching process to selectively remove the cladding layers to form second trenches, and forming a gate structure over the workpiece to fill the second trenches.

Abstract: A method includes providing a substrate, an isolation structure, and a fin extending from the substrate and through the isolation structure. The fin includes a stack of layers having first and second layers that are alternately stacked and have first and second semiconductor materials respectively. A topmost layer of the stack is one of the second layers. The structure further has a sacrificial gate stack engaging a channel region of the fin. The method further includes forming gate spacers and forming sidewall spacers on sidewalls of the fin in a source/drain region of the fin, wherein the sidewall spacers extend above a bottom surface of a topmost one of the first layers. The method further includes etching the fin in the source/drain region, resulting in a source/drain trench; partially recessing the second layers exposed in the source/drain trench, resulting in gaps; and forming dielectric inner spacers inside the gaps.

Abstract: A semiconductor structure includes a power rail, a dielectric layer over the power rail, a first source/drain feature over the dielectric layer, a via structure extending through the dielectric layer and electrically connecting the first source/drain feature to the power rail, and two dielectric fins disposed on both sides of the first source/drain feature. Each of the dielectric fins includes two seal spacers, a dielectric bottom cover between bottom portions of the seal spacers, a dielectric top cover between top portions of the seal spacers, and an air gap surrounded by the seal spacers, the dielectric bottom cover, and the dielectric top cover.

Abstract: The present disclosure provides semiconductor devices and methods of forming the same. A semiconductor device of the present disclosure includes a first source/drain feature and a second source/drain feature over a substrate, a plurality of channel members extending between the first source/drain feature and the second source/drain feature, a gate structure wrapping around each of the plurality of channel members, and at least one blocking feature. At least one of the plurality of channel members is isolated from the first source/drain feature and the second source/drain feature by the at least one blocking feature.

Abstract: Semiconductor device and the manufacturing method thereof are disclosed herein. An exemplary semiconductor device comprises a first semiconductor fin and a second semiconductor fin formed over a substrate, wherein lower portions of the first semiconductor fin and the second semiconductor fin are separated by an isolation structure; a first gate stack formed over the first semiconductor fin and a second gate stack formed over the second semiconductor fin; and a separation feature separating the first gate stack and the second gate stack, wherein the separation feature includes a first dielectric layer and a second dielectric layer with an air gap defined therebetween, and a bottom portion of the separation feature being inserted into the isolation structure.

Abstract: A semiconductor device structure is provided. The semiconductor device structure includes a substrate and a gate stack over the substrate. The semiconductor device structure also includes a spacer element over a sidewall of the gate stack. The spacer element is doped with a dopant, and the dopant contains halide. The spacer element has a first atomic concentration of the dopant near an inner surface of the spacer element adjacent to the gate stack. The spacer element has a second atomic concentration of the dopant near an outer surface of the spacer element. The first atomic concentration of the dopant is different than the second atomic concentration of the dopant.

Abstract: Multi-gate devices and methods for fabricating such are disclosed herein. An exemplary method includes forming a diffusion blocking layer on a semiconductor substrate; forming channel material layers over the diffusion blocking layer; patterning the semiconductor substrate, the channel material layers, and the diffusion blocking layer to form a trench in the semiconductor substrate, thereby defining an active region being adjacent the trench; filling the trench with a dielectric material layer and a solid doping source material layer containing a dopant; and driving the dopant from the solid doping source material layer to the active region, thereby forming an anti-punch-through (APT) feature in the active region.