Semiconductor devices and methods of manufacture thereof are disclosed. In some embodiments, a method of manufacturing a semiconductor device includes: providing a workpiece having a recess and a dielectric layer lining the recess; forming a conductive structure within the recess, wherein the conductive structure partially fills the recess; and recessing the dielectric layer, wherein, after the recessing, a top surface of the recessed dielectric layer is disposed within the recess.

A method of fabricating a semiconductor device is disclosed. The method includes forming a first gate stack over a substrate. The first gate stack includes a gate electrode, a first hard mask (HM) disposed over the gate electrode, and sidewall spacers along sidewalls of the first gate stack. The method also includes forming a first dielectric layer over the first gate stack, forming a second HM over the first HM and top surfaces of sidewall spacers, forming a second dielectric layer over the second HM and the first dielectric layer and removing the second and first dielectric layers to form a trench to expose a portion of the substrate while the second HM is disposed over the first gate stack.

A gate tie-down structure includes a gate structure including a gate conductor and gate spacers and inner spacers formed on the gate spacers. Trench contacts are formed on sides of the gate structure. An interlevel dielectric (ILD) has a thickness formed over the gate structure. A horizontal connection is formed within the thickness of the ILD over an active area connecting the gate conductor and one of the trench contacts over one of the inner spacers.

The present invention provides a metal oxide semiconductor (MOS) device, including a substrate, a gate structure on the substrate and a source/drain region disposed in the substrate at one side of the gate structure and in at least a part of an epitaxial structure, wherein the epitaxial structure includes a first buffer layer, which is an un-doped buffer layer, including a bottom portion disposed on a bottom surface of the epitaxial structure and a sidewall portion disposed on a concave sidewall of the epitaxial structure, an epitaxial layer which is encompassed by the first buffer layer, and a semiconductor layer which is disposed between the first buffer layer and the epitaxial layer. The source/drain region is disposed in the epitaxial structure.

A semiconductor device is provided that includes a pedestal of an insulating material present over at least one layer of a semiconductor material, and at least one fin structure in contact with the pedestal of the insulating material. Source and drain region structures are present on opposing sides of the at least one fin structure. At least one of the source and drain region structures includes at least two epitaxial material layers. A first epitaxial material layer is in contact with the at least one layer of semiconductor material. A second epitaxial material layer is in contact with the at least one fin structure. The first epitaxial material layer is separated from the at least one fin structure by the second epitaxial material layer. A gate structure present on the at least one fin structure.

A device includes a transistor. The transistor includes a plurality of stacked channels, a source/drain region coupled to the stacked channels, and a gate metal wrapped around the stacked channels. The transistor includes a plurality of inner spacers, each inner spacer being positioned laterally between the gate metal and the source/drain region and including a gap and an inner spacer liner layer between the gate metal and the source/drain region.

A semiconductor device includes a substrate having a first region and a second region, first active fins that extend in a first direction in the first region, second active fins that extend in the first direction in the second region, a first field insulating layer between the first active fins and that extend in a second direction, a second field insulating layer between the second active fins and extending in the second direction, a gate line that extends in the second direction on the second field insulating layer, the gate line linearly along with the first field insulating layer, a gate isolation layer between the first field insulating layer and the gate line, and gate spacers that extend in the second direction, the gate spacers in contact with both sidewalls of each of the first field insulating layer, the gate line, and the gate isolation layer.

A method includes receiving a semiconductor substrate. The semiconductor substrate has a top surface and includes a semiconductor element. Moreover, the semiconductor substrate has a fin structure formed thereon. The method also includes recessing the fin structure to form source/drain trenches, forming a first dielectric layer over the recessed fin structure in the source/drain trenches, implanting a dopant element into a portion of the fin structure beneath a bottom surface of the source/drain trenches to form an amorphous semiconductor layer, forming a second dielectric layer over the recessed fin structure in the source/drain trenches, annealing the semiconductor substrate, and removing the first and second dielectric layers. After the annealing and the removing steps, the method further includes further recessing the recessed fin structure to provide a top surface. Additionally, the method includes forming an epitaxial layer from and on the top surface.

A method of forming a semiconductor device includes forming a sacrificial layer over a first stack of nanostructures and an isolation region. A dummy gate structure is formed over the first stack of nanostructures, and a first portion of the sacrificial layer. A second portion of the sacrificial layer is removed to expose a sidewall of the first stack of nanostructures adjacent the dummy gate structure. A spacer layer is formed over the dummy gate structure. A first portion of the spacer layer physically contacts the first stack of nanostructures.

A method for fabricating a semiconductor device includes the steps of forming a gate structure on a substrate, forming an epitaxial layer adjacent to the gate structure, and then forming a first cap layer on the epitaxial layer. Preferably, a top surface of the first cap layer includes a curve concave upward and a bottom surface of the first cap layer includes a planar surface higher than a top surface of the substrate.