A transistor includes an insulating layer, a source region, a drain region, a channel layer, a ferroelectric layer, an interfacial layer, and a gate electrode. The source region and the drain region are respectively disposed on two opposite ends of the insulating layer. The channel layer is disposed on the insulating layer, the source region, and the drain region. The ferroelectric layer is disposed over the channel layer. The interfacial layer is sandwiched between the channel layer and the ferroelectric layer. The gate electrode is disposed on the ferroelectric layer.

A method for forming a stacked transistor includes forming a sacrificial cap over a first interconnect of a lower level transistor. The method further includes forming an upper level transistor above the sacrificial cap. The method further includes removing the sacrificial cap to form an opening such that the opening is delimited by the upper level transistor. The method further includes forming a second interconnect in the opening such that the second interconnect is in direct contact with the first interconnect.

A transistor structure includes a semiconductor substrate, a gate structure, a channel region, and a first conductive region. The semiconductor substrate has a semiconductor surface. The gate structure is above the semiconductor surface, and a first concave is formed to reveal the gate structure. The channel region is under the semiconductor surface. The first conductive region is electrically coupled to the channel region, and a second concave is formed to reveal the first conductive region. A mask pattern in a photolithography process is used to define the first concave, and the mask pattern only defines one dimension length of the first concave.

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.

A device includes a substrate, a gate structure, a capping layer, a source/drain region, a source/drain contact, and an air spacer. The gate structure wraps around at least one vertical stack of nanostructure channels over the substrate. The capping layer is on the gate structure. The source/drain region abuts the gate structure. The source/drain contact is on the source/drain region. The air spacer is between the capping layer and the source/drain contact.

A semiconductor device comprises an active pattern on a substrate, a pair of first source/drain patterns on the active pattern, a pair of second source/drain patterns on top surfaces of the first source/drain patterns, a gate electrode extending across the active pattern and having sidewalls that face the first and second source/drain patterns, a first channel structure extending across the gate electrode and connecting the first source/drain patterns, and a second channel structure extending across the gate electrode and connecting the second source/drain patterns. The gate electrode includes a first lower part between a bottom surface of the first channel structure and a top surface of the active pattern, and a first upper part between a top surface of the first channel structure and a bottom surface of the second channel structure. The first lower part has a thickness greater than that of the first upper part.

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 semiconductor structure and a method for manufacturing a semiconductor are provided. The semiconductor structure includes a channel pillar, a dielectric layer formed on the channel pillar, a via formed in the dielectric layer and electrically connected to the channel pillar, and a spacer formed between the dielectric layer and the via.

A semiconductor device includes a semiconductor film and a gate structure on the semiconductor film. The gate structure includes a multi-stepped gate dielectric on the semiconductor film and a gate electrode on the multi-stepped gate dielectric. The multi-stepped gate dielectric includes a first gate dielectric segment having a first thickness and a second gate dielectric segment having a second thickness that is less than the first thickness.