Abstract: A semiconductor device is provided. The semiconductor device includes a fin protruding from a semiconductor substrate and a gate structure over the fin. The semiconductor device also includes a source region and a drain region in the fin and at opposite sides of the gate structure. The semiconductor device further includes a gate spacer on a sidewall of the gate structure. The gate spacer includes an air-gap spacer and a sealing spacer above the air-gap spacer, an upper portion of the gate structure is laterally overlapping with the sealing spacer, and the bottom portion of the gate structure is laterally overlapping with the air gap spacer.

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: 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 device and a method of forming the same are provided. A semiconductor device according to the present disclosure includes a first source/drain feature, a second source/drain feature, a first semiconductor channel member and a second semiconductor channel member extending between the first and second source/drain features, and a first dielectric feature and a second dielectric feature each including a first dielectric layer and a second dielectric layer different from the first dielectric layer. The first and second dielectric features are sandwiched between the first and second semiconductor channel members.

Abstract: Provided are FinFET devices and methods of forming the same. A FinFET device includes a substrate, a first gate strip and a second gate strip. The substrate has at least one first fin in a first region, at least one second fin in a second region and an isolation layer covering lower portions of the first and second fins. The first fin includes a first material layer and a second material layer over the first material layer, and the interface between the first material layer and the second material layer is uneven. The first gate strip is disposed across the first fin. The second gate strip is disposed across the second fin.

Abstract: A method of fabricating semiconductor devices is provided. The method includes forming a fin structure on a substrate, in which the fin structure includes a fin stack of alternating first and second semiconductor layers and forming recesses in the fin stack at source and drain regions. The method also includes etching the second semiconductor layers to form recessed second semiconductor layers, and forming third semiconductor layers on sidewalls of the recessed second semiconductor layers. The method further includes epitaxially growing source and drain structures in the recesses, removing the recessed second semiconductor layers to form spaces between the first semiconductor layers, and oxidizing the third semiconductor layers to form inner spacers. In addition, the method includes forming a gate structure to fill the spaces and to surround the first semiconductor layers.

Abstract: Semiconductor structures and methods for forming the same are provided. The method includes forming a fin protruding from a substrate and forming an isolation structure surrounding the fin. The method also includes epitaxially growing channel fins on sidewalls of the fin over the isolation structure and etching the fin to form a space between the channel fins. The method further includes forming a gate structure to fill the space between the channel fins.

Abstract: Methods of fabricating semiconductor devices are provided. The method includes forming a gate structure over a substrate, forming a disposable spacer on a sidewall of the gate structure, and forming a source region and a drain region at opposite sides of the gate structure. The method also includes depositing an interlayer dielectric layer around the disposable spacer, and forming a first hard mask on the interlayer dielectric layer. The method further includes removing an upper portion of the gate structure, and removing the disposable spacer to form a trench between the gate structure and the interlayer dielectric layer. In addition, the method includes sealing the trench to form an air-gap spacer, and forming a second hard mask on the gate structure.

Abstract: A method that includes forming first semiconductor layers and second semiconductor layers disposed over a substrate, wherein the first and second semiconductor layers have different material compositions, are alternatingly disposed, and extend over first and second regions of the substrate; patterning the first and the second semiconductor layers to form a first fin in the first region and a second fin in the second region; removing the first semiconductor layers from the first and second fins such that a first portion of the patterned second semiconductor layers becomes first suspended nanostructures in the first fin and that a second portion of the patterned second semiconductor layers becomes second suspended nanostructures in the second fin; forming third semiconductor layers on the second suspended nanostructures in the second fin; and performing an anneal process to drive materials contained in the third semiconductor layers into corresponding second suspended nanostructures in the second fin.

Abstract: A method of fabricating semiconductor devices is provided. The method includes forming a fin structure on a substrate, in which the fin structure includes a fin stack of alternating first and second semiconductor layers and forming recesses in the fin stack at source and drain regions. The method also includes etching the second semiconductor layers to form recessed second semiconductor layers, and forming third semiconductor layers on sidewalls of the recessed second semiconductor layers. The method further includes epitaxially growing source and drain structures in the recesses, removing the recessed second semiconductor layers to form spaces between the first semiconductor layers, and oxidizing the third semiconductor layers to form inner spacers. In addition, the method includes forming a gate structure to fill the spaces and to surround the first semiconductor layers.

Abstract: A method of fabricating semiconductor devices is provided. The method includes forming a fin protruding from a substrate, and forming a disposable mandrel fin on the fin. The method also includes epitaxially growing channel fins on sidewalls of the disposable mandrel fin. The method further includes removing the disposable mandrel fin to form a space between the channel fins, and forming a gate structure to fill the space between the channel fins and to wrap the channel fins. In addition, the method includes forming source and drain structures on opposite sides of 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: 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: 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, wherein 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, the silicide layer continuously surrounding the extended portion of the epitaxial S/D feature over the isolation structure.

Abstract: A method of fabricating semiconductor devices is provided. The method includes forming a fin protruding from a substrate, and forming a disposable mandrel fin on the fin. The method also includes epitaxially growing channel fins on sidewalls of the disposable mandrel fin. The method further includes removing the disposable mandrel fin to form a space between the channel fins, and forming a gate structure to fill the space between the channel fins and to wrap the channel fins. In addition, the method includes forming source and drain structures on opposite sides of the gate structure.

Abstract: Provided are FinFET devices and methods of forming the same. A FinFET device includes a substrate, a first gate strip and a second gate strip. The substrate has at least one first fin in a first region, at least one second fin in a second region and an isolation layer covering lower portions of the first and second fins. The first fin includes a first material layer and a second material layer over the first material layer, and the interface between the first material layer and the second material layer is uneven. The first gate strip is disposed across the first fin. The second gate strip is disposed across the second fin.

Abstract: A method that includes forming first semiconductor layers and second semiconductor layers disposed over a substrate, wherein the first and second semiconductor layers have different material compositions, are alternatingly disposed, and extend over first and second regions of the substrate; patterning the first and the second semiconductor layers to form a first fin in the first region and a second fin in the second region; removing the first semiconductor layers from the first and second fins such that a first portion of the patterned second semiconductor layers becomes first suspended nanostructures in the first fin and that a second portion of the patterned second semiconductor layers becomes second suspended nanostructures in the second fin; forming third semiconductor layers on the second suspended nanostructures in the second fin; and performing an anneal process to drive materials contained in the third semiconductor layers into corresponding second suspended nanostructures in the second fin.

Abstract: Methods of fabricating semiconductor devices are provided. The method includes forming a gate structure over a substrate, forming a disposable spacer on a sidewall of the gate structure, and forming a source region and a drain region at opposite sides of the gate structure. The method also includes depositing an interlayer dielectric layer around the disposable spacer, and forming a first hard mask on the interlayer dielectric layer. The method further includes removing an upper portion of the gate structure, and removing the disposable spacer to form a trench between the gate structure and the interlayer dielectric layer. In addition, the method includes sealing the trench to form an air-gap spacer, and forming a second hard mask on the gate structure.

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