Abstract: A semiconductor device is provided. The semiconductor device includes a silicon layer over a fin, a doped semiconductor layer over the fin and adjoining the silicon layer, a plurality of channel layers over the silicon layer, a source/drain structure on the doped semiconductor layer and adjoining plurality of channel layers, and a plurality of inner spacers between the plurality of channel layers.

Abstract: A semiconductor device is provided. The semiconductor device includes a plurality of channel layers stacked over a semiconductor substrate and spaced apart from one another, a source/drain structure adjoining the plurality of channel layers, a gate structure wrapping around the plurality of channel layers, and a first inner spacer between the gate structure and the source/drain structure and between the plurality of channel layers. The first inner spacer is made of an oxide of a semiconductor material.

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

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: 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: 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: 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: 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 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: Methods for manufacturing a semiconductor structure are provided. The method includes alternately stacking first semiconductor material layers and second semiconductor layers over a substrate and patterning the first semiconductor material layers and the second semiconductor layers to form a first fin structure and a second fin structure. The method also includes forming an insulating layer around the first fin structure and the second fin structure and forming a dielectric fin structure over the insulating layer and spaced apart from the first fin structure and the second fin structure. The method also includes forming a first source/drain structure attached to the first fin structure and forming a semiconductor layer covering the first source/drain structure. The method also includes oxidizing the semiconductor layer to form an oxide layer and forming a second source/drain structure attached to the second fin structure after the oxide layer is formed.

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: A method includes forming a semiconductor fin over a substrate; forming a gate structure over the semiconductor fin; forming a helmet layer lining the gate structure and the semiconductor fin; etching the helmet layer to remove portions of the helmet layer from opposite sidewalls of the gate structure, wherein the remaining helmet layer comprises a first remaining portion on a top surface of the gate structure and a second remaining portion on a top surface of the semiconductor fin; forming a spacer layer covering the gate structure, wherein the spacer layer is in contact with the first remaining portion and the second remaining portion of the remaining helmet layer; etching the spacer layer and the remaining helmet layer to form gate spacers, wherein each of the gate spacers has a stepped sidewall; and forming source/drain epitaxy structures on opposite sides of the gate structure.

Abstract: A semiconductor device includes a first epitaxial feature disposed in a first device region of the semiconductor device, a second epitaxial feature disposed in a second device region of the semiconductor device, a first silicide layer disposed on the first epitaxial feature, a second silicide layer disposed on the second epitaxial feature, a metal layer disposed on the first silicide layer, a first contact plug landing on the metal layer, and a second contact plug landing on the second silicide layer. The metal layer and the second silicide layer each include a first metal element. The first silicide layer includes a second metal element different from the first metal element.

Abstract: A semiconductor structure includes a semiconductor fin extending from a substrate, a source/drain (S/D) feature disposed over the semiconductor fin, a silicide layer disposed over the S/D feature, where the silicide layer extends along a sidewall of the S/D feature, and an etch-stop layer (ESL) disposed along a sidewall of the silicide 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 void is between the silicide layer and the dielectric 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: A semiconductor device includes a semiconductor substrate, a first epitaxial feature having a first semiconductor material over the semiconductor substrate, and a second epitaxial feature having a second semiconductor material over the semiconductor substrate. The second semiconductor material being different from the first semiconductor material. The semiconductor device further includes a first silicide layer on the first epitaxial feature, a second silicide layer on the second epitaxial feature, a metal layer on the first silicide layer, a first contact feature over the metal layer, and a second contact feature over the second silicide layer. A first number of layers between the first contact feature and the first epitaxial feature is greater than a second number of layers between the second contact feature and the second epitaxial feature.

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