Abstract: In in a method of manufacturing a semiconductor device, an interlayer dielectric (ILD) layer is formed over an underlying structure. The underlying structure includes a gate structure disposed over a channel region of a fin structure, and a first source/drain epitaxial layer disposed at a source/drain region of the fin structure. A first opening is formed over the first source/drain epitaxial layer by etching a part of the ILD layer and an upper portion of the first source/drain epitaxial layer. A second source/drain epitaxial layer is formed over the etched first source/drain epitaxial layer. A conductive material is formed over the second source/drain epitaxial layer.

Abstract: A method comprises growing an epitaxial layer on a first region of a first wafer while remaining a second region of the first wafer exposed; forming a first dielectric layer over the epitaxial layer and the second region; forming a first transistor on a second wafer; forming a second dielectric layer over the first transistor; bonding the first and second dielectric layers; and forming second and third transistors on the epitaxial layer and on the second region of the first wafer, respectively.

Abstract: A method according to the present disclosure includes depositing, over a substrate, a stack including channel layers interleaved by sacrificial layers, forming a first fin structure and a second fin in a first area and a second area of the substrate, depositing a first dummy gate stack over the first fin structure and a second dummy gate stack over the second fin structure, recessing source/drain regions of the first fin structure and second fin structure to form first source/drain trenches and second source/drain trenches, selectively and partially etching the sacrificial layers to form first inner spacer recesses and second inner spacer recesses, forming first inner spacer features in the first inner spacer recesses, and forming second inner spacer features in the second inner spacer recesses. A composition of the first inner spacer features is different from a composition of the second inner spacer features.

Abstract: A method of semiconductor fabrication includes providing a semiconductor structure having a substrate and first, second, third, and fourth fins above the substrate. The method further includes forming an n-type epitaxial source/drain (S/D) feature on the first and second fins, forming a p-type epitaxial S/D feature on the third and fourth fins, and performing a selective etch process on the semiconductor structure to remove upper portions of the n-type epitaxial S/D feature and the p-type epitaxial S/D feature such that more is removed from the n-type epitaxial S/D feature than the p-type epitaxial S/D feature.

Abstract: A semiconductor device and method of manufacturing the semiconductor device are provided. An exemplary semiconductor device comprises a fin disposed over a substrate, wherein the fin includes a channel region and a source/drain region; a gate structure disposed over the substrate and over the channel region of the fin; a source/drain feature epitaxially grown in the source/drain region of the fin, wherein the source/drain feature includes a top epitaxial layer and a lower epitaxial layer formed below the top epitaxial layer, and the lower epitaxial layer includes a wavy top surface; and a contact having a wavy bottom surface matingly engaged with the wavy top surface of the lower epitaxial layer of the source/drain feature.

Abstract: Methods and semiconductor structures are provided. A method according to the present disclosure includes receiving a workpiece that includes a first gate structure disposed over a first active region, a second gate structure disposed over a second active region, a first gate spacer extending along a sidewall of the first gate structure and disposed at least partially over a top surface of the first active region, a second gate spacer extending along a sidewall of the second gate structure and disposed at least partially over a top surface of the second active region, and a source/drain feature. The method also includes treating a portion of the first gate spacer and a portion of the second gate spacer with a remote radical of hydrogen or oxygen, removing the treated portions, and after the removal, depositing a metal fill material over the source/drain feature.

Abstract: A semiconductor device and method of manufacturing the semiconductor device are provided. An exemplary semiconductor device comprises a fin disposed over a substrate, wherein the fin includes a channel region and a source/drain region; a gate structure disposed over the substrate and over the channel region of the fin; a source/drain feature epitaxially grown in the source/drain region of the fin, wherein the source/drain feature includes a top epitaxial layer and a lower epitaxial layer formed below the top epitaxial layer, and the lower epitaxial layer includes a wavy top surface; and a contact having a wavy bottom surface matingly engaged with the wavy top surface of the lower epitaxial layer of the source/drain feature.

Abstract: In an embodiment, a device includes: a nanostructure; and a source/drain region adjoining a channel region of the nanostructure, the source/drain region including: a first epitaxial layer on a sidewall of the nanostructure, the first epitaxial layer including a germanium-free semiconductor material and a p-type dopant; a second epitaxial layer on the first epitaxial layer, the second epitaxial layer including a germanium-containing semiconductor material and the p-type dopant; and a third epitaxial layer on the second epitaxial layer, the third epitaxial layer including the germanium-containing semiconductor material and the p-type dopant.

Abstract: A method according to the present disclosure includes depositing, over a substrate, a stack including channel layers interleaved by sacrificial layers, forming a first fin structure and a second fin in a first area and a second area of the substrate, depositing a first dummy gate stack over the first fin structure and a second dummy gate stack over the second fin structure, recessing source/drain regions of the first fin structure and second fin structure to form first source/drain trenches and second source/drain trenches, selectively and partially etching the sacrificial layers to form first inner spacer recesses and second inner spacer recesses, forming first inner spacer features in the first inner spacer recesses, and forming second inner spacer features in the second inner spacer recesses. A composition of the first inner spacer features is different from a composition of the second inner spacer features.

Abstract: A semiconductor structure and a method of forming the same are provided. A semiconductor structure according to the present disclosure includes a first channel member and a second channel member disposed over the first channel member, a first channel extension feature coupled to the first channel member, a second channel extension feature coupled to the second channel member, and an inner spacer feature disposed between the first channel extension feature and the second channel extension feature.

Abstract: A method for fabricating a semiconductor device that includes a merged source/drain feature extending between two adjacent fin structures is provided. An air gap is formed under the merged source/drain feature. Forming the epitaxial feature includes growing a first epitaxial feature having a first portion over the first fin structure and a second portion over the second fin structure, growing a second epitaxial feature over the first and second portions of the first epitaxial feature, and growing a third epitaxial feature over the second epitaxial feature. The second epitaxial feature includes a merged portion between the first fin structure and the second fin structure.

Abstract: A semiconductor structure and a method of forming the same are provided. A semiconductor structure according to the present disclosure includes a first channel member and a second channel member disposed over the first channel member, a first channel extension feature coupled to the first channel member, a second channel extension feature coupled to the second channel member, and an inner spacer feature disposed between the first channel extension feature and the second channel extension feature.

Abstract: The present application provides a semiconductor device and the method of making the same. The method includes recessing a fin extending from a substrate, forming a base epitaxial feature on the recessed fin, forming a bar-like epitaxial feature on the base epitaxial feature, and forming a conformal epitaxial feature on the bar-like epitaxial feature. The forming of the bar-like epitaxial feature includes in-situ doping the bar-like epitaxial feature with an n-type dopant at a first doping concentration. The forming of the conformal epitaxial feature includes in-situ doping the conformal epitaxial feature with a second doping concentration greater than the first doping concentration.

Abstract: The present application provides a semiconductor device and the method of making the same. The method includes recessing a fin extending from a substrate, forming a base epitaxial feature on the recessed fin, forming a bar-like epitaxial feature on the base epitaxial feature, and forming a conformal epitaxial feature on the bar-like epitaxial feature. The forming of the bar-like epitaxial feature includes in-situ doping the bar-like epitaxial feature with an n-type dopant at a first doping concentration. The forming of the conformal epitaxial feature includes in-situ doping the conformal epitaxial feature with a second doping concentration greater than the first doping concentration.

Abstract: A field effect transistor includes a substrate and spacers over the substrate. The field effect transistor includes a channel recess cavity between the spacers, wherein a bottom-most surface of the channel recess cavity is parallel to the substrate top surface. The field effect transistor includes a gate stack, wherein the gate stack includes a bottom portion in the channel recess cavity and a top portion outside the channel recess cavity, the gate stack further includes a gate dielectric layer extending from the channel recess cavity along sidewalls of each of the pair of spacers, and the gate dielectric layer directly contacts the substrate below substrate top surface. The field effect transistor includes a strained source/drain (S/D) below the substrate top surface, wherein the strained S/D extends below the gate stack. The field effect transistor further includes a source/drain (S/D) extension substantially conformably surrounding the strained S/D.

Abstract: A method of semiconductor fabrication includes providing a semiconductor structure having a substrate and first, second, third, and fourth fins above the substrate. The method further includes forming an n-type epitaxial source/drain (S/D) feature on the first and second fins, forming a p-type epitaxial S/D feature on the third and fourth fins, and performing a selective etch process on the semiconductor structure to remove upper portions of the n-type epitaxial S/D feature and the p-type epitaxial S/D feature such that more is removed from the n-type epitaxial S/D feature than the p-type epitaxial S/D feature.

Abstract: A semiconductor structure and a method of forming the same are provided. A semiconductor structure according to the present disclosure includes a first channel member and a second channel member disposed over the first channel member, a first channel extension feature coupled to the first channel member, a second channel extension feature coupled to the second channel member, and an inner spacer feature disposed between the first channel extension feature and the second channel extension feature.

Abstract: A semiconductor device and method of manufacturing the semiconductor device are provided. An exemplary semiconductor device comprises a fin disposed over a substrate, wherein the fin includes a channel region and a source/drain region; a gate structure disposed over the substrate and over the channel region of the fin; a source/drain feature epitaxially grown in the source/drain region of the fin, wherein the source/drain feature includes a top epitaxial layer and a lower epitaxial layer formed below the top epitaxial layer, and the lower epitaxial layer includes a wavy top surface; and a contact having a wavy bottom surface matingly engaged with the wavy top surface of the lower epitaxial layer of the source/drain feature.

Abstract: A method of semiconductor fabrication includes providing a semiconductor structure having a substrate and first, second, third, and fourth fins above the substrate. The method further includes forming an n-type epitaxial source/drain (S/D) feature on the first and second fins, forming a p-type epitaxial S/D feature on the third and fourth fins, and performing a selective etch process on the semiconductor structure to remove upper portions of the n-type epitaxial S/D feature and the p-type epitaxial S/D feature such that more is removed from the n-type epitaxial S/D feature than the p-type epitaxial S/D feature.

Abstract: A method for fabricating a semiconductor device having a substantially undoped channel region includes providing a substrate having a fin extending from the substrate. An in-situ doped layer is formed on the fin. By way of example, the in-situ doped layer may include an in-situ doped well region formed by an epitaxial growth process. In some examples, the in-situ doped well region includes an N-well or a P-well region. After formation of the in-situ doped layer on the fin, an undoped layer is formed on the in-situ doped layer, and a gate stack is formed over the undoped layer. The undoped layer may include an undoped channel region formed by an epitaxial growth process. In various examples, a source region and a drain region are formed adjacent to and on either side of the undoped channel region.