Abstract: 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.

Abstract: In a method of manufacturing a semiconductor device, a support layer is formed over a substrate. A patterned semiconductor layer made of a first semiconductor material is formed over the support layer. A part of the support layer under a part of the semiconductor layer is removed, thereby forming a semiconductor wire. A semiconductor shell layer made of a second semiconductor material different from the first semiconductor material is formed around the semiconductor wire.

Abstract: Various transistors, such as horizontal gate-all-around transistors, and methods of fabricating such are disclosed herein. An exemplary transistor includes a first nanowire and a second nanowire that include a first semiconductor material, a gate that wraps a channel region of the first nanowire and the second nanowire, and source/drain feature that wraps source/drain regions of the first nanowire and the second nanowire. The source/drain feature includes a second semiconductor material that is configured differently than the first semiconductor material. In some implementations, the transistor further includes a fin-like semiconductor layer disposed over a substrate. The first nanowire and the second nanowire are disposed over the fin-like semiconductor layer, such that the first nanowire, the second nanowire, and the fin-like semiconductor layer extend substantially parallel to one another along the same length-wise direction.

Abstract: A semiconductor device structure is provided. The semiconductor device structure includes a substrate having a base and a multilayer stack over the base. The semiconductor device structure includes a gate stack over the substrate and wrapping around the multilayer stack. The semiconductor device structure includes a dielectric layer over the base and covering a first sidewall of the multilayer stack. A first upper surface of the dielectric layer is lower than a second upper surface of the multilayer stack. The semiconductor device structure includes a stressor over a second sidewall of the multilayer stack. The first sidewall is opposite to the second sidewall.

Abstract: A device includes an active region, a gate structure, an epitaxial structure, an epitaxial layer, a metal alloy layer, a contact, and a contact etch stop layer. The gate structure is across the active region. The epitaxial structure is above the active region and adjacent the gate structure. The epitaxial layer is above the epitaxial structure. The metal alloy layer is above the epitaxial layer. The contact is above the metal alloy layer. The contact etch stop layer lines sidewalls of the epitaxial structure. The metal alloy layer is spaced apart from the contact etch stop layer.

Abstract: A semiconductor device structure is provided. The semiconductor device structure includes a substrate having a base portion and a fin portion over the base portion. The semiconductor device structure includes an epitaxial structure over the fin portion. The semiconductor device structure includes a dielectric fin over the base portion. The semiconductor device structure includes a silicide layer between the dielectric fin and the epitaxial structure. A distance between the silicide layer and the dielectric fin increases toward the base portion.

Abstract: The present disclosure provides a method of semiconductor fabrication that includes forming a semiconductor fin protruding from a substrate, the semiconductor fin including a plurality of first semiconductor layers of a first semiconductor material and second semiconductor layers of a second semiconductor material alternatively stacked, the second semiconductor material being different from the first semiconductor material in composition; forming a first gate stack on the semiconductor fin; forming a recess in the semiconductor fin within a source/drain (S/D) region adjacent to the first gate stack, a sidewall of the first and second semiconductor material layers being exposed within the recess; performing an etching process to the semiconductor fin, resulting in an undercut below the first gate stack; epitaxially growing on the sidewall of the semiconductor fin to fill in the undercut with a semiconductor extended feature of the first semiconductor material; and growing an epitaxial S/D feature from the rece

Abstract: A method includes forming an epitaxy semiconductor layer over a semiconductor substrate, and etching the epitaxy semiconductor layer and the semiconductor substrate to form a semiconductor strip, which includes an upper portion acting as a mandrel, and a lower portion under the mandrel. The upper portion is a remaining portion of the epitaxy semiconductor layer, and the lower portion is a remaining portion of the semiconductor substrate. The method further includes growing a first semiconductor fin starting from a first sidewall of the mandrel, growing a second semiconductor fin starting from a second sidewall of the mandrel. The first sidewall and the second sidewall are opposite sidewalls of the mandrel. A first transistor is formed based on the first semiconductor fin. A second transistor is formed based on the second semiconductor fin.

Abstract: A semiconductor structure is received that has a first and second fins. A first epitaxial feature is formed on the first fin and has a first type dopant. A first capping layer is formed over the first epitaxial feature. A second epitaxial feature is formed on the second fin and has a second type dopant different from the first type dopant. A first metal is deposited on the second epitaxial feature and on the first capping layer. A first silicide layer is formed from the first metal and the second epitaxial feature, and a second capping layer is formed from the first metal and the first capping layer. The second capping layer is selectively removed. A second metal is deposited on the first epitaxial feature and over the second epitaxial feature. A second silicide layer is formed from the second metal and the first epitaxial feature.

Abstract: A semiconductor device according to the present disclosure includes a first isolation feature and a second isolation feature, a fin structure extending lengthwise along a first direction and sandwiched between the first isolation feature and the second isolation feature along a second direction perpendicular to the first direction, a first channel member disposed over the first isolation feature, a second channel member disposed over the second isolation feature, and a gate structure disposed over and wrapping around the first channel member and the second channel member.

Abstract: A method for forming a semiconductor device structure is provided. The method includes forming a first gate stack over a substrate. The substrate has a base and a first fin structure over the base, and the first gate stack wraps around a first upper portion of the first fin structure. The method includes partially removing the first fin structure, which is not covered by the first gate stack. The method includes forming a first mask layer over a first sidewall of the first fin structure. The method includes forming a first stressor over a second sidewall of the first fin structure while the first mask layer covers the first sidewall. The first sidewall is opposite to the second sidewall. The method includes removing the first mask layer. The method includes forming a dielectric layer over the base and the first stressor. The dielectric layer covers the first sidewall.

Abstract: A semiconductor device structure is provided. The semiconductor device structure includes a substrate having a base portion and a fin portion over the base portion. The semiconductor device structure includes an epitaxial structure over the fin portion. The semiconductor device structure includes a dielectric fin over the base portion. A top surface of the dielectric fin is close to the epitaxial structure. The semiconductor device structure includes a silicide layer wrapping around the epitaxial structure and partially between the dielectric fin and the epitaxial structure. The silicide layer covers a lower surface of the epitaxial structure, and the lower surface is lower than the top surface of the dielectric fin.

Abstract: A semiconductor device having a first region and a second region is provided. The first region has a first protruding structure and a second protruding structure. The second region has a third protruding structure and a fourth protruding structure. First, second, third, and fourth epi-layers are formed on the first, second, third, and fourth protruding structures, respectively. The first and second epi-layers are covered with a first photoresist layer while leaving the third and fourth epi-layers exposed. A dielectric layer is formed over the first photoresist layer and over the third and fourth epi-layers. A portion of the dielectric layer is covered with a second photoresist layer. The portion of the dielectric layer is formed over the third and fourth epi-layers. Portions of the dielectric layer not protected by the first and second photoresist layers are etched. The first and second photoresist layers are removed.

Abstract: A semiconductor structure includes a first fin, which includes a first plurality of suspended nanostructures vertically stacked over one another, each of the first plurality of suspended nanostructure having a center portion that has a first cross section, and a second fin, which includes a second plurality of suspended nanostructures vertically stacked over one another, the first plurality of suspended nanostructures and the second plurality of suspended nanostructures having different material compositions, each of the second plurality of suspended nanostructure having a center portion that has a second cross section, wherein a shape or an area of the first cross section is different from that of the second cross section.

Abstract: A method includes forming a gate stack over a semiconductor region, and forming a first gate spacer on a sidewall of the gate stack. The first gate spacer includes an inner sidewall spacer, and a dummy spacer portion on an outer side of the inner sidewall spacer. The method further includes removing the dummy spacer portion to form a trench, and forming a dielectric layer to seal a portion of the trench as an air gap. The air gap and the inner sidewall spacer in combination form a second gate spacer. A source/drain region is formed to have a portion on an outer side of the second gate spacer.

Abstract: A method includes forming an epitaxy semiconductor layer over a semiconductor substrate, and etching the epitaxy semiconductor layer and the semiconductor substrate to form a semiconductor strip, which includes an upper portion acting as a mandrel, and a lower portion under the mandrel. The upper portion is a remaining portion of the epitaxy semiconductor layer, and the lower portion is a remaining portion of the semiconductor substrate. The method further includes growing a first semiconductor fin starting from a first sidewall of the mandrel, growing a second semiconductor fin starting from a second sidewall of the mandrel. The first sidewall and the second sidewall are opposite sidewalls of the mandrel. A first transistor is formed based on the first semiconductor fin. A second transistor is formed based on the second semiconductor fin.

Abstract: The present disclosure provides a semiconductor device that includes a semiconductor fin disposed over a substrate, an isolation structure at least partially surrounding the fin, an epitaxial source/drain (S/D) feature disposed over the semiconductor fin, where an extended portion of the epitaxial S/D feature extends over the isolation structure, and a silicide layer disposed on the epitaxial S/D feature, where the silicide layer covers top, bottom, sidewall, front, and back surfaces of the extended portion of the S/D feature.

Abstract: In a method for manufacturing a semiconductor device, a gate structure is formed over a channel layer and an isolation insulating layer. A first sidewall spacer layer is formed on a side surface of the gate structure. A sacrificial layer is formed so that an upper portion of the gate structure with the first sidewall spacer layer is exposed from the sacrificial layer and a bottom portion of the gate structure with the first sidewall spacer layer is embedded in the first sacrificial layer. A space is formed between the bottom portion of the gate structure and the sacrificial layer by removing at least part of the first sidewall spacer layer. After the first sidewall spacer layer is removed, an air gap is formed between the bottom portion of the gate structure and the sacrificial layer by forming a second sidewall spacer layer over the gate structure.

Abstract: Semiconductor device and the manufacturing method thereof are disclosed herein. An exemplary method comprises forming a fin over a substrate, wherein the fin comprises a first semiconductor layer and a second semiconductor layer including different semiconductor materials, and the fin comprises a channel region and a source/drain region; forming a dummy gate structure over the channel region of the fin and over the substrate; etching a portion of the fin in the source/drain region to form a trench therein, wherein a bottom surface of the trench is below a bottom surface of the second semiconductor layer; selectively removing an edge portion of the second semiconductor layer in the channel region such that the second semiconductor layer is recessed; forming a sacrificial structure around the recessed second semiconductor layer and over the bottom surface of the trench; and epitaxially growing a source/drain feature in the source/drain region of the fin.

Abstract: The present disclosure describes an inner spacer structure for a semiconductor device and a method for forming the same. The method for forming the inner spacer structure in the semiconductor device can include forming a vertical structure over a substrate, forming a gate structure over a portion of the vertical structure, exposing sidewalls of the portion of the vertical structure, forming multiple spacers over the sidewalls of the portion of the vertical structure, and forming a void in each of the multiple spacers.