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.

A multi-stack semiconductor device includes: a lower-stack transistor structure including a lower active region and a lower gate structure, the lower active region including a lower channel structure, and the lower gate structure surrounding the lower channel structure; an upper-stack transistor structure vertically stacked above the lower-stack transistor structure, and including an upper active region and an upper gate structure, the upper active region including an upper channel structure, and the upper gate structure surrounding the upper channel structure; and at least one gate contact plug contacting a top surface of the lower gate structure, wherein the lower gate structure and the upper gate structure have a substantially same size in a plan view, and wherein the lower gate structure is not entirely overlapped by the upper gate structure in a vertical direction.

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 is provided. The semiconductor structure includes a first nanostructure stacked over and spaced apart from a second nanostructure, a gate stack wrapping around the first nanostructure and the second nanostructure, a source/drain feature adjoining the first nanostructure and the second nanostructure, and a first inner spacer layer interposing the gate stack and the source/drain feature and interposing the first nanostructure and the second nanostructure. A dopant in the source/drain feature has a first concentration at an interface between the first inner spacer layer and the source/drain feature and a second concentration at a first distance away from the interface. The first concentration is higher than the second concentration.

An integrated circuit (IC) device includes a fin-type active region on a substrate. A mesa-type channel region protrudes from the fin-type active region in a vertical direction. The mesa-type channel region is integrally connected with the fin-type active region. A gate line substantially surrounds a mesa-type channel region on the fin-type active region. A gate dielectric film is between the mesa-type channel region and the gate line. The mesa-type channel region includes: a plurality of round convex portions, which are convex toward the gate line; a concavo-convex sidewall, which includes a portion of each of the plurality of round convex portions and faces the gate line; and at least one void, which is inside the mesa-type channel region.

The integrated circuit (IC) structure includes a semiconductor substrate, a first active region, a dummy fill region, a second active region, first metal gate structures, and second metal gate structures. The first active region is on the semiconductor substrate. The dummy fill region is on the semiconductor substrate. The second active region is on the semiconductor substrate and spaced apart from the first active region by the dummy fill region. The first metal gate structures extend in the first active region and have a first gate pitch and a first gate width. The second metal gate structures extend in the second active region and have a second gate width greater than the first gate width and a second gate pitch being an integer times the first gate pitch, and the integer being two or more.

A device including first nanosheet structures each including a first number of nanosheets, second nanosheet structures each including a second number of nanosheets that is different than the first number of nanosheets, and a plurality of rows including first rows and second rows. Where each of the first nanosheet structures is in a respective one of the first rows, each of the second nanosheet structures is in a respective one of the second rows, at least two of the first rows are adjacent one another, and at least two of the second rows are adjacent one another.

A semiconductor device includes: an active pattern extending in a first direction on a substrate; a first lower source/drain pattern and a second lower source/drain pattern provided on the active pattern and spaced apart from each other in the first direction; a first upper source/drain pattern provided on the first lower source/drain pattern; a second upper source/drain pattern provided on the second lower source/drain pattern; and a gate electrode crossing the active pattern and extending in a second direction intersecting the first direction. The gate electrode includes an overlapping portion overlapping the active pattern in a third direction perpendicular to the first direction and the second direction. A length of the overlapping portion in the second direction is less than a length of the first lower source/drain pattern in the second direction.

A semiconductor device includes active regions extending in a first direction on a substrate; a gate electrode intersecting the active regions on the substrate, extending in a second direction, and including a contact region protruding upwardly; and an interconnection line on the gate electrode and connected to the contact region, wherein the contact region includes a lower region having a first width in the second direction and an upper region located on the lower region and having a second width smaller than the first width in the second direction, and wherein at least one side surface of the contact region in the second direction has a point at which an inclination or a curvature is changed between the lower region and the upper region.