A semiconductor device includes a plurality of semiconductor layers vertically separated from one another. The semiconductor device includes a gate structure that comprises a lower portion and an upper portion. The lower portion wraps around each of the plurality of semiconductor layers. The semiconductor device includes a gate spacer that extends along a sidewall of the upper portion of the gate structure and comprises a first layer and a second layer. The first layer is in contact with a first portion of the sidewall and the second layer is in contact with a second portion of the sidewall.

In an example, a method includes depositing a first sidewall spacer layer over a substrate having a layer stack including alternating layers of a nanosheet and a sacrificial layer, and a dummy gate formed over the layer stack, the first sidewall spacer layer formed over the dummy gate. The method includes depositing a metal-containing liner over the first sidewall spacer layer; forming a first sidewall spacer along the dummy gate by anisotropically etching the metal-containing liner and the first sidewall spacer layer; performing an anisotropic etch back process to form a plurality of vertical recesses in the layer stack; laterally etching the layer stack and form a plurality of lateral recesses between adjacent nanosheets; depositing a second sidewall spacer layer to fill the plurality of lateral recesses; and etching a portion of the second sidewall spacer layer to expose tips of the nanosheet layers.

An integrated circuit includes a nanosheet transistor having a plurality of stacked channels, a gate electrode surrounding the stacked channels, a source/drain region, and a source/drain contact. The integrated circuit includes a first dielectric layer between the gate metal and the source/drain contact, a second dielectric layer on the first dielectric layer, and a cap metal on the first gate metal and on a hybrid fin structure. The second dielectric layer is on the hybrid fin structure between the cap metal and the source/drain contact.

A semiconductor device includes a semiconductor feature, a low-k dielectric feature that is formed on the semiconductor feature, and a Si-containing layer that contains elements of silicon and that covers over the low-k dielectric feature. The Si-containing layer can prevent the low-k dielectric feature from being damaged in etch and/or annealing processes for manufacturing the semiconductor device.

Confined epitaxial regions for semiconductor devices and methods of fabricating semiconductor devices having confined epitaxial regions are described. For example, a semiconductor structure includes a plurality of parallel semiconductor fins disposed above and continuous with a semiconductor substrate. An isolation structure is disposed above the semiconductor substrate and adjacent to lower portions of each of the plurality of parallel semiconductor fins. An upper portion of each of the plurality of parallel semiconductor fins protrudes above an uppermost surface of the isolation structure. Epitaxial source and drain regions are disposed in each of the plurality of parallel semiconductor fins adjacent to a channel region in the upper portion of the semiconductor fin. The epitaxial source and drain regions do not extend laterally over the isolation structure. The semiconductor structure also includes one or more gate electrodes, each gate electrode disposed over the channel region of one or more of the plurality of parallel semiconductor fins.

A device includes plural semiconductor fins, a gate structure, an interlayer dielectric (ILD) layer, and an isolation dielectric. The gate structure is across the semiconductor fins. The ILD surrounds the gate structure. The isolation dielectric is at least between the semiconductor fins and has a thermal conductivity greater than a thermal conductivity of the ILD layer.

In a method of manufacturing a semiconductor device, a fin structure including a stacked layer of first and second semiconductor layers and a hard mask layer over the stacked layer is formed. A sacrificial cladding layer is formed over at least sidewalls of the exposed hard mask layer and stacked layer. An etching is performed to remove lateral portions of the sacrificial cladding layer, thereby leaving the sacrificial cladding layer on sidewalls of the exposed hard mask layer and stacked layer. A first dielectric layer and a second dielectric layer made of a different material than the first dielectric layer are formed. The second dielectric layer is recessed, and a third dielectric layer made of a different material than the second dielectric layer is formed on the recessed second dielectric layer. During the etching operation, a protection layer is formed over the sacrificial cladding layer.

A semiconductor device includes a substrate including a first region, a second region, and active regions extending in a first direction in the first region and in the second region; gate electrodes on the first region and the second region, the gate electrodes intersecting the active regions and extending in a second direction; a plurality of channel layers spaced apart from each other in a third direction on active regions of the active regions and encompassed by the gate electrodes, the third direction being perpendicular to an upper surface of the substrate; and first source/drain regions and second source/drain regions in portions of the active regions that are recessed on both sides of the gate electrodes, the first source/drain regions and the second source/drain regions being connected to the plurality of channel layers, wherein the first source/drain regions are in the first region, and the second source/drain regions are in the second region, wherein an end portion of each of the first source/drain regions in the second direction in a plan view includes a tip region protruding in the second direction, and wherein an end portion of each of the second source/drain regions in the second direction in the plan view extends flatly in the first direction.

Integrated circuit devices and methods of forming the same are provided. The methods may include forming a dummy channel region and an active region of a substrate, forming a bottom source/drain region on the active region, forming a gate electrode on one of opposing side surfaces of the dummy channel region, and forming first and second spacers on the opposing side surfaces of the dummy channel region, respectively. The gate electrode may include a first portion on the one of the opposing side surfaces of the dummy channel region and a second portion between the bottom source/drain region and the first spacer. The methods may also include forming a bottom source/drain contact by replacing the first portion of the gate electrode with a conductive material. The bottom source/drain contact may electrically connect the second portion of the gate electrode to the bottom source/drain region.

A semiconductor device structure and a method for forming a semiconductor device structure are provided. The semiconductor device structure includes a stack of channel structures over a semiconductor fin and a gate stack wrapped around the channel structures. The semiconductor device structure also includes a source/drain epitaxial structure adjacent to the channel structures and multiple inner spacers. Each of the inner spacers is between the gate stack and the source/drain epitaxial structure. The semiconductor device structure further includes an isolation structure between the semiconductor fin and the source/drain epitaxial structure.