Inner spacers between a source/drain region of a nanostructure transistor and sacrificial nanostructure layers of the nanostructure transistor are removed prior to formation of a gate structure of the nanostructure transistor. The sacrificial nanostructure layers are removed, and then the inner spacers are removed. The sacrificial nanostructure layers are then replaced with the gate structure of the nanostructure transistor such that the gate structure and the source/drain region are spaced apart by air gaps that result from the removal of the inner spacers. The dielectric constant (or relative permittivity) of the air gaps between the source/drain region and the gate structure is less than the dielectric constant of the material of the inner spacers. The lesser dielectric constant of the air gaps reduces the amount of capacitance between the source/drain region and the gate structure.

A method includes forming a stack of layers, which includes a plurality of semiconductor nanostructures, and a plurality of sacrificial layers. The plurality of semiconductor nanostructures and the plurality of sacrificial layers are arranged alternatingly. The method further includes laterally recessing the plurality of sacrificial layers to form lateral recesses, depositing a spacer layer extending into the lateral recesses, trimming the spacer layer to form inner spacers, and performing a treatment process to reduce dielectric constant values of the inner spacers.

A memory device includes a substrate, first semiconductor fin, second semiconductor fin, first gate structure, second gate structure, first gate spacer, and a second gate spacer. The first gate structure crosses the first semiconductor fin. The second gate structure crosses the second semiconductor fin, the first gate structure extending continuously from the second gate structure, in which in a top view of the memory device, a width of the first gate structure is greater than a width of the second gate structure. The first gate spacer is on a sidewall of the first gate structure. The second gate spacer extends continuously from the first gate spacer and on a sidewall of the second gate structure, in which in the top view of the memory device, a width of the first gate spacer is less than a width of the second gate spacer.

The present disclosure provides a method of manufacturing a semiconductor device. The method includes forming a stack of first semiconductor layers and second semiconductor layers over a substrate, etching the stack to form a source/drain (S/D) recess in exposing the substrate, and forming an S/D formation assistance region in the S/D recess. The S/D formation assistance region is partially embedded in the substrate and includes a semiconductor seed layer embedded in an isolation layer. The isolation layer electrically isolates the semiconductor seed layer from the substrate. The method also includes epitaxially growing an S/D feature in the S/D recess from the semiconductor seed layer. The S/D feature is in physical contact with the second semiconductor layers.

Embodiments of the disclosure are in the field of advanced integrated circuit structure fabrication and, in particular, 10 nanometer node and smaller integrated circuit structure fabrication and the resulting structures. In an example, an integrated circuit structure includes a first silicon fin having a longest dimension along a first direction. A second silicon fin having a longest dimension is along the first direction. An insulator material is between the first silicon fin and the second silicon fin. A gate line is over the first silicon fin and over the second silicon fin along a second direction, the second direction orthogonal to the first direction, the gate line having a first side and a second side, wherein the gate line has a discontinuity over the insulator material, the discontinuity filled by a dielectric plug.

Embodiments of the disclosure are in the field of advanced integrated circuit structure fabrication and, in particular, 10 nanometer node and smaller integrated circuit structure fabrication and the resulting structures. In an example, an integrated circuit structure includes a fin. An isolation structure surrounds a lower fin portion, the isolation structure comprising an insulating material having a top surface, and a semiconductor material on a portion of the top surface of the insulating material, wherein the semiconductor material is separated from the fin. A gate dielectric layer is over the top of an upper fin portion and laterally adjacent the sidewalls of the upper fin portion, the gate dielectric layer further on the semiconductor material on the portion of the top surface of the insulating material. A gate electrode is over the gate dielectric layer.

A semiconductor structure includes a fin disposed on a substrate, the fin including a channel region comprising a plurality of channels vertically stacked over one another, the channels comprising germanium distributed therein. The semiconductor structure further includes a gate stack engaging the channel region of the fin and gate spacers disposed between the gate stack and the source and drain regions of the fin, wherein each channel of the channels includes a middle section wrapped around by the gate stack and two end sections engaged by the gate spacers, wherein a concentration of germanium in the middle section of the channel is higher than a concentration of germanium in the two end sections of the channel, and wherein the middle section of the channel further includes a core portion and an outer portion surrounding the core portion with a germanium concentration profile from the core portion to the outer portion.

A semiconductor device structure and a formation method are provided. The method includes forming a fin structure over a substrate. The fin structure has multiple sacrificial layers and multiple semiconductor layers laid out in an alternating manner. The method also includes partially removing the fin structure to form a recess exposing side surfaces of the semiconductor layers and the sacrificial layers and forming multiple inner spacers covering the side surfaces of the sacrificial layers. The method further includes recessing the semiconductor layers from the side surfaces of the semiconductor layers after the inner spacers are formed and partially removing the inner spacers so that each of the inner spacers becomes thinner. In addition, the method includes forming an epitaxial structure on the side surfaces of the semiconductor layers.

Embodiments of the disclosure are in the field of advanced integrated circuit structure fabrication and, in particular, 10 nanometer node and smaller integrated circuit structure fabrication and the resulting structures. In an example, an integrated circuit structure includes first and second gate dielectric layers over a fin. First and second gate electrodes are over the first and second gate dielectric layers, respectively, the first and second gate electrodes both having an insulating cap having a top surface. First dielectric spacer are adjacent the first side of the first gate electrode. A trench contact structure is over a semiconductor source or drain region adjacent first and second dielectric spacers, the trench contact structure comprising an insulating cap on a conductive structure, the insulating cap of the trench contact structure having a top surface substantially co-planar with the insulating caps of the first and second gate electrodes.

A method and structures are used to fabricate a nanosheet semiconductor device. Nanosheet fins including nanosheet stacks including alternating silicon (Si) layers and silicon germanium (SiGe) layers are formed on a substrate and etched to define a first end and a second end along a first axis between which each nanosheet fin extends parallel to every other nanosheet fin. The SiGe layers are undercut in the nanosheet stacks at the first end and the second end to form divots, and a dielectric is deposited in the divots. The SiGe layers between the Si layers are removed before forming source and drain regions of the nanosheet semiconductor device such that there are gaps between the Si layers of each nanosheet stack, and the dielectric anchors the Si layers. The gaps are filled with an oxide that is removed after removing the dummy gate and prior to forming the replacement gate.