A semiconductor device is provided. The semiconductor device includes: an active pattern provided on a substrate and extending in a first direction; a pair of source/drain patterns provided on the active pattern and spaced apart from each other in the first direction; a plurality of channel layers vertically stacked and spaced apart from each other on the active pattern between the pair of source/drain patterns; a gate electrode extending in a second direction between the pair of source/drain patterns, the gate electrode being provided on the active pattern and surrounding the plurality of channel layers, and the second direction intersecting the first direction; and a gate spacer provided between the plurality of channel layers, and between the gate electrode and the pair of source/drain patterns. The gate spacer includes a plurality of first spacer patterns and a plurality of second spacer patterns that are alternately stacked on sidewalls of the pair of source/drain patterns.

A semiconductor device may include: an active pattern on a substrate and extending in a first direction; a plurality of source/drain patterns on the active pattern and spaced apart from each other in the first direction; a gate electrode between the plurality of source/drain patterns that crosses the active pattern and extends in a second direction intersecting the first direction; and a plurality of channel patterns stacked on the active pattern and configured to connect two or more of the source/drain patterns to each other. The channel patterns may be spaced apart from each other. Each of the channel patterns may include a first portion between the gate electrode and the source/drain patterns, and a plurality of second portions connected to the first portion and overlapped with the gate electrode in a direction perpendicular to a plane defined by an upper surface of the substrate.

Semiconductor device and the manufacturing method thereof are disclosed herein. An exemplary semiconductor device comprises a substrate, at least two gate structures disposed over the substrate, each of the at least two gate structures including a gate electrode and a spacer disposed along sidewalls of the gate electrode, wherein the spacer includes a refill portion and a bottom portion, the refill portion of the spacer has a funnel shape such that a top surface of the refill portion of the spacer is larger than a bottom surface of the refill portion of the spacer, and a source/drain contact disposed over the substrate and between the spacers of the at least two gate structures.

Source and drain formation techniques disclosed herein provide FinFETs with reduced channel resistance and reduced drain-induced barrier lowering. An exemplary three-step etch method for forming a source/drain recess in a source/drain region of a fin includes a first anisotropic etch, an isotropic etch, and a second anisotropic etch. The first anisotropic etch and the isotropic etch are tuned to define a location of a source/drain tip. A depth of the source/drain recess after the first anisotropic etch and the isotropic etch is less than a target depth. The second anisotropic etch is tuned to extend the depth of the source/drain recess to the target depth. The source/drain tip is near a top of the fin to reduce channel resistance while a bottom portion of the source/drain recess is spaced a distance from a gate footing that can minimize DIBL. The source/drain recess is filled with an epitaxial semiconductor material.

Techniques are provided to form semiconductor devices having a multi-layer spacer structure. In an example, a semiconductor device includes a semiconductor region extending between a source region and a drain region, and a gate layer extending over the semiconductor region. A spacer structure made up of one or more dielectric layers is present along a sidewall of the gate structure and along a sidewall of the source region or the drain region. The spacer structure has three different portions: a first portion along the sidewall of the gate, a second portion along the sidewall of the source or drain region, and a third portion that connects between the first two portions. The third portion of the spacer structure has a multi-layer configuration while the first and second portions have a fewer number of material layers.

A semiconductor device includes a first gate structure and a second gate structure over a fin, a dielectric cut pattern sandwiched by the first and second gate structures, and a liner layer surrounding the dielectric cut pattern. The dielectric cut pattern is spaced apart from the fin and extends further from the substrate than a first gate electrode of the first gate structure and a second gate electrode of the second gate structure. The semiconductor device further includes a conductive feature sandwiched by the first and second gate structures. The conductive feature is divided by the conductive feature into a first segment and a second segment. The first segment of the conductive feature is above a source/drain region of the fin.

Semiconductor structures and methods are provided. An exemplary method according to the present disclosure includes receiving a fin-shaped structure comprising a first channel region and a second channel region, a first and a second dummy gate structures disposed over the first and the second channel regions, respectively. The method also includes removing a portion of the first dummy gate structure, a portion of the first channel region and a portion of the substrate under the first dummy gate structure to form a trench, forming a hybrid dielectric feature in the trench, removing a portion of the hybrid dielectric feature to form an air gap, sealing the air gap, and replacing the second dummy gate structure with a gate stack after sealing the air gap.

A method of forming a semiconductor device is provided. The method includes providing a substrate having a first region and a second region; forming a plurality of trenches in the first region of the substrate; forming a multi-layer stack over the substrate and in the trenches; and patterning the multi-layer stack and the substrate to form first nanostructures over first fins in the first region and second nanostructures over second fins in the second region, where the multi-layer stack includes at least one of first semiconductor layers and at least one of second semiconductor layer stacked alternately, and the plurality of trenches are in corresponding ones of the first fins.

A semiconductor structure includes a fin extending from a substrate and oriented lengthwise in a first direction, where the fin includes a stack of semiconductor layers, an isolation feature disposed over the substrate and oriented lengthwise in a second direction perpendicular to the first direction, where the isolation feature is disposed adjacent to the fin, and a metal gate structure having a top portion disposed over the stack of semiconductor layers and a bottom portion interleaved with the stack of semiconductor layers. Furthermore, a sidewall of the bottom portion of the metal gate structure is defined by a sidewall of the isolation feature, and the top portion of the metal gate structure laterally extends over a top surface of the isolation feature.

Semiconductor structures and methods for manufacturing the same are provided. The semiconductor structure includes a substrate and first nanostructures and second nanostructures formed over the substrate. The semiconductor structure also includes a gate structure including a first portion wrapping around the first nanostructures and a second portion wrapping around the second nanostructures. The semiconductor structure also includes a dielectric feature sandwiched between the first portion and the second portion of the gate structure. In addition, the dielectric feature includes a bottom portion and a top portion over the bottom portion, and the top portion of the dielectric feature includes a shell layer and a core portion surrounded by the shell layer.