A method includes forming a protruding semiconductor stack including a plurality of sacrificial layers and a plurality of nanostructures, with the plurality of sacrificial layers and the plurality of nanostructures being laid out alternatingly. The method further includes forming a dummy gate structure on the protruding semiconductor stack, etching the protruding semiconductor stack to form a source/drain recess, and forming a source/drain region in the source/drain recess. The formation of the source/drain region includes growing first epitaxial layers. The first epitaxial layers are grown on sidewalls of the plurality of nanostructures, and a cross-section of each of the first epitaxial layers has a quadrilateral shape. The first epitaxial layers have a first dopant concentration. The formation of the source/drain region further includes growing a second epitaxial layer on the first epitaxial layers. The second epitaxial layer has a second dopant concentration higher than the first dopant concentration.

A method for forming a semiconductor structure is provided. The method includes forming a fin structure over a substrate. The fin structure includes a protection layer and alternating first and second semiconductor layers over the protection layer. The method also includes etching the fin structure to form a source/drain recess, forming a sacrificial contact in the source/drain recess, forming a source/drain feature over the sacrificial contact in the source/drain recess, removing the first semiconductor layers of the fin structure, thereby forming a plurality of nanostructures, forming a gate stack wrapping around the nanostructures, removing the substrate thereby exposing the protection layer and the sacrificial contact and replacing the sacrificial contact with a contact plug.

An apparatus including a substrate and a first nanosheet device located on the substrate. A second nanosheet device is located on the substrate, where the second nanosheet device is adjacent to the first nanosheet device. At least one first gate located on the first nanosheet device and the at least one first gate has a first width. At least one second gate located on the second nanosheet device and the at least one second gate has a second width. The first width and the second width are substantially the same. A diffusion break located between the first nanosheet device and the second nanosheet device. The diffusion break prevents the first nanosheet device from contacting the second nanosheet device, and the diffusion break has a third width. The third width is larger than the first width and the second width.

A field effect transistor (FET) structure upon a substrate formed by forming a stack of nanosheets upon a semiconductor substrate, the stack including alternating layers of a compound semiconductor material and an elemental semiconductor material, forming a dummy gate structure upon the stack of nanosheets, recessing the stack of nanosheets in alignment with the dummy gate structure, recessing the compound semiconductor layers beyond the edges of the dummy gate, yielding indentations between adjacent semiconductor nanosheets. Further by filling the indentations with a bi-layer dielectric material, epitaxially growing source/drain regions adjacent to the nanosheet stack and bi-layer dielectric material, removing remaining portions of the compound semiconductor nanosheet layers, recessing the bi-layer dielectric material to expose an inner material layer, and forming gate structure layers in contact with first and second dielectric materials of the bi-layer dielectric material.

Techniques herein include methods of forming channel structures for field effect transistors having a channel current path parallel to a surface of a substrate. 3D in-situ horizontal or lateral growth of the channel and source/drain regions allows for a custom doping in the 3D horizontal nanosheet direction for NMOS and PMOS devices. An ultra-short channel length is achieved with techniques herein because the channel is epitaxially grown in the 3D horizontal nanosheet direction at the monolayer level. Since the channel is grown in a dielectric cavity, a precise channel cross sectional area can be tuned.

Techniques for recovering the width of a top gate spacer in a field-effect transistor (FET) device are provided. In one aspect, a FET device includes: at least one gate; source/drain regions present on opposite sides of the at least one gate; gate spacers offsetting the at least one gate from the source/drain regions, wherein each of the gate spacers includes an L-shaped spacer alongside the at least one gate and a dielectric liner disposed on the L-shaped spacer; and at least one channel interconnecting the source/drain regions. A method of forming a FET device is also provided which includes recovering the width of the top gate spacer using the dielectric liner.

A method includes depositing a first semiconductor layer and a second semiconductor layer over a substrate; patterning the first semiconductor layer, the second semiconductor layer, and the substrate to form a first nanostructure, a second nanostructure, and a semiconductor fin; forming a recess in the first nanostructure and the second nanostructure, the recess exposing the semiconductor fin; epitaxially growing a first layer in the recess, a first portion of the first layer being disposed along a first sidewall of the first nanostructure, a second portion of the first layer being disposed along the semiconductor fin, the first portion of the first layer comprising two sidewalls extending toward a middle of the recess, the first portion of the first layer further comprising a first surface most distal from the first sidewall and directly interposed between the two sidewalls, the first portion being physically separated from the second portion; and epitaxially growing a second layer over the first portion of the first layer and over the second portion of the first layer, the second layer physically connecting the first portion of the first layer to the second portion of the first layer.

A semiconductor device is provided. The semiconductor device includes: first, second and third active patterns on a logic cell region of a substrate and are spaced apart from each other in a first direction; first and second gate electrodes, the first gate electrode crossing the first active pattern and the second gate electrode crossing the second active pattern; a first separation pattern provided between the first and second active patterns; a second separation pattern provided between the second and third active patterns; a first gate insulating layer interposed between the first gate electrode and the first active pattern; and a first gate cutting pattern interposed between the first and second gate electrodes, and in contact with a top surface of the first separation pattern. The first separation pattern is wider than the second separation pattern, and the first gate insulating layer extends between the first gate electrode and the first separation pattern, and contacts side and top surfaces of the first separation pattern.

An integrated circuit includes a first nanostructure transistor having a first gate electrode and a second nanostructure transistor having a second gate electrode. A dielectric isolation structure is between the first and second gate electrodes. A gate connection metal is on a portion of the top surface of the first gate electrode and on a portion of a top surface of the second gate electrode. The gate connection metal is patterned to expose other portions of the top surfaces of the first and second gate electrodes adjacent to the dielectric isolation structure. A conductive via contacts the exposed portion of the top surface of the second gate electrode.

A semiconductor device structure is provided. The semiconductor device structure includes a substrate having a base and a fin structure over the base. The semiconductor device structure includes an isolation structure over the base and surrounding a lower portion of the fin structure. The semiconductor device structure includes a gate stack wrapped around an upper portion of the fin structure. The semiconductor device structure includes a source/drain structure partially embedded in the isolation structure and the lower portion of the fin structure. The source/drain structure has an undoped semiconductor layer and a first doped layer over the undoped semiconductor layer, and the undoped semiconductor layer separates the first doped layer from the isolation structure.