Abstract: Various examples of an integrated circuit device and a method for forming the device are disclosed herein. In an example, a method includes receiving a workpiece that includes a substrate, and a device fin extending above the substrate. The device fin includes a channel region. A portion of the device fin adjacent the channel region is etched, and the etching creates a source/drain recess and forms a dielectric barrier within the source/drain recess. The workpiece is cleaned such that a bottommost portion of the dielectric barrier remains within a bottommost portion of the source/drain recess. A source/drain feature is formed within the source/drain recess such that the bottommost portion of the dielectric barrier is disposed between the source/drain feature and a remainder of the device fin.

Abstract: A method for forming a semiconductor device structure is provided. The method includes providing a substrate. The method includes forming a nanostructure stack over the substrate. The method includes forming a gate stack over the nanostructure stack and the substrate. The method includes removing the first nanostructure forming a first gap between the substrate and the second nanostructure. The method includes forming a first spacer layer in the first gap and a gate spacer over a sidewall of the gate stack. The method includes partially removing the nanostructure stack, which is not covered by the gate stack and the gate spacer, to form a first trench in the nanostructure stack. The method includes forming a source/drain structure in the first trench and over the first spacer layer.

Abstract: A method includes depositing a dummy semiconductor layer and a first semiconductor layer over a substrate, forming spacers on sidewalls of the dummy semiconductor layer, forming a first epitaxial material in the substrate, exposing the dummy semiconductor layer and the first epitaxial material, where exposing the dummy semiconductor layer and the first epitaxial material includes thinning a backside of the substrate, etching the dummy semiconductor layer to expose the first semiconductor layer, where the spacers remain over and in contact with end portions of the first semiconductor layer while etching the dummy semiconductor layer, etching portions of the first semiconductor layer using the spacers as a mask, and replacing a second epitaxial material and the first epitaxial material with a backside via, the backside via being electrically coupled to a source/drain region of a first transistor.

Abstract: 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.

Abstract: A device a includes a substrate, two source/drain (S/D) features over the substrate, and semiconductor layers suspended over the substrate and connecting the two S/D features. The device further includes a dielectric layer disposed between two adjacent layers of the semiconductor layers and an air gap between the dielectric layer and one of the S/D features, where a ratio between a length of the air gap to a thickness of the first dielectric layer is in a range of 0.1 to 1.0.

Abstract: A semiconductor device includes a gate stack, an epitaxy structure, a first spacer, a second spacer, and a dielectric residue. The gate stack is over a substrate. The epitaxy structure is formed raised above the substrate. The first spacer is on a sidewall of the gate stack. The first spacer and the epitaxy structure define a void therebetween. The second spacer seals the void between the first spacer and the epitaxy structure. The dielectric residue is in the void and has an upper portion and a lower portion under the upper portion. The upper portion of the dielectric residue has a silicon-to-nitrogen atomic ratio higher than a silicon-to-nitrogen atomic ratio of the lower portion of the dielectric residue.

Abstract: Semiconductor device and the manufacturing method thereof are disclosed. An exemplary semiconductor device comprises semiconductor layers over a substrate, wherein the semiconductor layers are stacked up and separated from each other, each semiconductor layer includes a first portion in a first channel region of the substrate and a second portion in a second channel region of the substrate, epitaxial layers formed in a source/drain region between the first channel region and the second channel region, wherein the epitaxial layers are separated from each other and each epitaxial layer is formed between the first portion and the second portion of each semiconductor layer, and a conductive feature wrapping each of the epitaxial layers.

Abstract: Methods for performing a pre-clean process to remove an oxide in semiconductor devices and semiconductor devices formed by the same are disclosed. In an embodiment, a method includes forming a shallow trench isolation region over a semiconductor substrate; forming a gate stack over the shallow trench isolation region; etching the shallow trench isolation region adjacent the gate stack using an anisotropic etching process; and after etching the shallow trench isolation region with the anisotropic etching process, etching the shallow trench isolation region with an isotropic etching process, process gases for the isotropic etching process including hydrogen fluoride (HF) and ammonia (NH3).

Abstract: In a method of manufacturing a semiconductor device, a fin structure in which first semiconductor layers and second semiconductor layers are alternately stacked is formed over a substrate, a sacrificial gate structure is formed over the fin structure, a source/drain region of the fin structure is etched thereby forming a source/drain space, ends of the first semiconductor layers is laterally etched, an insulating layer is formed on a sidewall of the source/drain space, the insulating layer is partially etched, thereby forming one or more inner spacers on an etched end face of each of one or more first semiconductor layers and leaving a part of the insulating layer as a remaining insulating layer, and a source/drain epitaxial layer is formed in the source/drain space. After the source/drain epitaxial layer is formed, an end face of at least one of the second semiconductor layers is covered by the remaining insulating layer.

Abstract: A semiconductor device includes a fin-shape base protruding from a substrate, channel structures suspended above the fin-shape base, a gate structure wrapping around each of the channel structures, a source/drain (S/D) epitaxial feature abutting the channel structures and directly above a top surface of the fin-shape base, inner spacers interposing the S/D epitaxial feature and the gate structure, and a dielectric layer disposed vertically between the top surface of the fin-shape base and a bottom surface of the S/D epitaxial feature.

Abstract: A semiconductor device includes a substrate; two source/drain (S/D) regions over the substrate; a gate stack over the substrate and between the two S/D regions; a spacer layer covering sidewalls of the gate stack; an S/D contact metal over one of the two S/D regions; a first dielectric layer covering sidewalls of the S/D contact metal; and an inter-layer dielectric (ILD) layer covering the first dielectric layer, the spacer layer, and the gate stack, thereby defining a gap. A material of a first sidewall of the gap is different from materials of a top surface and a bottom surface of the gap, and a material of a second sidewall of the gap is different from the materials of the top surface and the bottom surface of the gap.

Abstract: A semiconductor device includes a substrate; two source/drain (S/D) regions over the substrate; a gate stack over the substrate and between the two S/D regions; a spacer layer covering sidewalls of the gate stack; an S/D contact metal over one of the two S/D regions; a first dielectric layer covering sidewalls of the S/D contact metal; and an inter-layer dielectric (ILD) layer covering the first dielectric layer, the spacer layer, and the gate stack, thereby defining a gap. A material of a first sidewall of the gap is different from materials of a top surface and a bottom surface of the gap, and a material of a second sidewall of the gap is different from the materials of the top surface and the bottom surface of the gap.

Abstract: Multi-gate devices and methods for fabricating such are disclosed herein. An exemplary method includes forming a semiconductor stack on a substrate, wherein the semiconductor stack includes a first semiconductor layers and a second semiconductor layers alternatively disposed, the first semiconductor layers and the second semiconductor layers being different in composition; patterning the semiconductor stack to form a semiconductor fin; forming a dielectric fin next to the semiconductor fin; forming a first gate stack on the semiconductor fin and the dielectric fin; etching to a portion of the semiconductor fin within a source/drain region, resulting in a source/drain recess; and epitaxially growing a source/drain feature in the source/drain recess, defining an airgap spanning between a sidewall of the source/drain feature and a sidewall of the dielectric fin.

Abstract: A semiconductor device includes a fin stack, a gate structure on the fin stack, a source region on a first side of the gate structure, a drain region on a second side of the gate structure opposite the first side, and a source contact extending to and connecting the source region. The source region and the drain region are asymmetric.

Abstract: In a method of manufacturing a semiconductor device, a fin structure, in which first and second semiconductor layers are alternately stacked over a substrate, is formed, a source/drain region of the fin structure is etched thereby forming a source/drain space, ends of the first semiconductor layers are laterally etched in the source/drain space, a first insulating layer is formed on a sidewall of the source/drain space, the first insulating layer is partially etched, thereby forming a first bottom spacer at a bottom of the source/drain space, a second insulating layer is formed on the sidewall of the source/drain space, the second insulating layer is partially etched, thereby forming inner spacers on end faces of the first semiconductor layers and leaving a part of the second insulating layer as a second bottom spacer at the bottom of the source/drain space, and a source/drain epitaxial layer is formed in the source/drain space.

Abstract: A method of fabricating a fin-like field effect transistor (FinFET) device includes providing a semiconductor substrate having a region for forming p-type metal-oxide-semiconductor (PMOS) devices and a region for forming n-type metal-oxide-semiconductor (PMOS) devices, forming fin structures in both regions of the substrate separated by isolation features, first forming source/drain (S/D) features in the PMOS region, and subsequently forming S/D features in the NMOS region. First forming the PMOS S/D features and then forming the NMOS S/D features results in a greater extent of loss of isolation features in the PMOS region than in the NMOS region.

Abstract: A method includes forming a fin in a substrate. The fin is etched to create a source/drain recess. A source/drain feature is formed in the source/drain recess, in which a lattice constant of the source/drain feature is greater than a lattice constant of the fin. An epitaxy coat is grown over the source/drain feature, in which a lattice constant of the epitaxy coat is smaller than a lattice constant of the fin.

Abstract: Semiconductor device and the manufacturing method thereof are disclosed herein. An exemplary semiconductor device comprises a semiconductor fin formed on a substrate; and a gate structure disposed over a channel region of the semiconductor fin, the gate structure including a gate dielectric layer and a gate electrode, wherein the gate dielectric layer includes a bottom portion and a side portion, and the gate electrode is separated from the side portion of the gate dielectric layer by a first air gap.

Abstract: A semiconductor structure includes an active region including a source/drain feature, a contact protruding from a bottom surface of the source/drain feature, a first dielectric layer disposed directly below the active region and surrounding the contact, an air gap disposed between the contact and the first dielectric layer, and a seal disposed between the contact and the first dielectric layer, such that the air gap is disposed between the seal and the source/drain feature.

Abstract: A semiconductor structure and a method of forming the same are provided. In an embodiment, a semiconductor structure includes a first plurality of channel members over a backside dielectric layer, a second plurality of channel members over the backside dielectric layer, a first gate structure over and wrapping around each of the first plurality of channel members, a second gate structure over and wrapping around each of the second plurality of channel members, and a through-substrate contact that extends between the first plurality of channel members and the second plurality of channel members, between the first gate structure and the second gate structure, and through the backside dielectric layer.