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.

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 lateral diffusion metal-oxide semiconductor (LDMOS) device includes a first gate structure and a second gate structure extending along a first direction on a substrate, a first source region extending along the first direction on one side of the first gate structure, a second source region extending along the first direction on one side of the second gate structure, a drain region extending along the first direction between the first gate structure and the second gate structure, a guard ring surrounding the first gate structure and the second gate structure, and a shallow trench isolation (STI) surrounding the guard ring.

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 high voltage transistor structure including a substrate, a first isolation structure, a second isolation structure, a gate structure, a first source and drain region, and a second source and drain region is provided. The first isolation structure and the second isolation structure are disposed in the substrate. The gate structure is disposed on the substrate, at least a portion of the first isolation structure, and at least a portion of the second isolation structure. The first source and drain region and the second source and drain region are located in the substrate on two sides of the first isolation structure and the second isolation structure. The depth of the first isolation structure is greater than the depth of the second isolation structure.

A semiconductor device includes a semiconductor layer, a drift region, a source area, a well region, a drain area, and a dielectric film. The drift region and the source area are formed in the semiconductor layer. The well region is formed in the semiconductor layer and between the drift region and the source area. The drain area is formed in the drift region. The dielectric film is formed in the drift region and is located between the source area and the drain area. The dielectric film includes a proximate end portion and a distal end portion which are proximate to and distal from the source area, respectively, and which are asymmetrical to each other.

Gallium nitride (GaN) integrated circuit technology is described. In an example, an integrated circuit structure includes a substrate including silicon, the substrate having a top surface. A first trench is in the substrate, the first trench having a first width. A second trench is in the substrate, the second trench having a second width less than the first width. A first island is in the first trench, the first island including gallium and nitrogen and having first corner facets below the top surface of the substrate. A second island is in the second trench, the second island including gallium and nitrogen and having second corner facets below the top surface of the substrate.