A semiconductor device includes a plurality of channel layers vertically separated from one another. The semiconductor device also includes an active gate structure comprising a lower portion and an upper portion. The lower portion wraps around each of the plurality of channel layers. The semiconductor device further includes a gate spacer extending along a sidewall of the upper portion of the active gate structure. The gate spacer has a bottom surface. Moreover, a dummy gate dielectric layer is disposed between the gate spacer and a topmost channel layer of plurality of channel layers. The dummy gate dielectric layer is in contact with a top surface of the topmost channel layer, the bottom surface of the gate spacer, and the sidewall of the gate structure.

A semiconductor device includes a semiconductor substrate having first and second regions therein, a first lower semiconductor pattern, which protrudes from the semiconductor substrate in the first region and extends in a first direction across the semiconductor substrate, and a first gate electrode, which extends across the first lower semiconductor pattern and the semiconductor substrate in a second direction. A plurality of semiconductor sheet patterns are provided, which are spaced apart from each other in a third direction to thereby define a vertical stack of semiconductor sheet patterns, on the first lower semiconductor pattern. A first gate insulating film is provided, which separates the plurality of semiconductor sheet patterns from the first gate electrode. A second lower semiconductor pattern is provided, which protrudes from the semiconductor substrate in the second region. A plurality of wire patterns are provided, which are spaced apart from each other on the second lower semiconductor pattern. A second gate insulating film is wrapped around each of the plurality of wire patterns.

An IC structure includes first, second, and third circuits. The first circuit includes a first semiconductor fin, a first gate electrode extending across the first semiconductor fin, and a first gate dielectric layer spacing the first gate electrode apart from the first semiconductor fin. The second circuit includes a second semiconductor fin, a second gate electrode extending across the second semiconductor fin, and a second gate dielectric layer spacing the second gate electrode apart from the second semiconductor fin. The third circuit includes a third semiconductor fin, a third gate electrode extending across the third semiconductor fin, and a third gate dielectric layer spacing the third gate electrode apart from the third semiconductor fin. The first gate dielectric layer has a greater thickness than the second gate dielectric layer. The third semiconductor fin has a smaller width than the second semiconductor fin.

A semiconductor structure and a method of forming the same are provided. In an embodiment, an exemplary semiconductor structure includes a number of channel members over a substrate, a gate structure wrapping around each of the number of channel members, a dielectric fin structure disposed adjacent to the gate structure, the dielectric fin structure includes a first dielectric layer disposed over the substrate and in direct contact with the first gate structure, a second dielectric layer disposed over the first dielectric layer, and a third dielectric layer. The third dielectric is disposed over the second dielectric layer and spaced apart from the first dielectric layer and the gate structure by the second dielectric layer. The dielectric fin structure also includes an isolation feature disposed directly over the third dielectric layer.

Devices and methods for layout-dependent voltage handling improvement in switch stacks. In some embodiments, a switching device can include a first terminal and a second terminal, a radio-frequency signal path implemented between the first terminal and the second terminal, and a plurality of switching elements connected in series to form a stack between the second terminal and ground. The stack can have an orientation relative to the radio-frequency signal path, and the switching elements can have a non-uniform distribution of a first parameter based in part on the orientation of the stack.

Gate-all-around integrated circuit structures having asymmetric source and drain contact structures, and methods of fabricating gate-all-around integrated circuit structures having asymmetric source and drain contact structures, are described. For example, an integrated circuit structure includes a vertical arrangement of nanowires above a fin. A gate stack is over the vertical arrangement of nanowires. A first epitaxial source or drain structure is at a first end of the vertical arrangement of nanowires. A second epitaxial source or drain structure is at a second end of the vertical arrangement of nanowires. A first conductive contact structure is coupled to the first epitaxial source or drain structure. A second conductive contact structure is coupled to the second epitaxial source or drain structure. The second conductive contact structure is deeper along the fin than the first conductive contact structure.

An integrated circuit (IC) structure includes a first transistor and a second transistor. The first transistor includes a first active region and a first gate disposed on the first active region, in which the first gate has a first effective gate length along a first direction parallel to a lengthwise direction of the first active region. The second transistor includes a second active region and a second gate disposed on the second active region, and includes a plurality of gate structures arranged along the first direction and separated from each other, in which the second gate has a second effective gate length along the first direction, the second effective gate length is n times the first effective gate length, and n is a positive integer greater than 1.

A device includes a gate stack; a gate spacer on a sidewall of the gate stack; a source/drain region adjacent the gate stack; a silicide; and a source/drain contact electrically connected to the source/drain region through the silicide. The silicide includes a conformal first portion in the source/drain region, the conformal first portion comprising a metal and silicon; and a conformal second portion over the conformal first portion, the conformal second portion further disposed on a sidewall of the gate spacer, the conformal second portion comprising the metal, silicon, and nitrogen.

A semiconductor structure has a frontside and a backside. The semiconductor structure includes an isolation structure at the backside; one or more transistors at the frontside, wherein the one or more transistors have source/drain epitaxial features; two metal plugs through the isolation structure and contacting two of the source/drain electrodes from the backside; and a dielectric liner filling a space between the two metal plugs, wherein the dielectric liner partially or fully surrounds an air gap between the two metal plugs.

A semiconductor device including: a first structure including: a first semiconductor pattern protruding from a substrate, the first semiconductor pattern being a channel; a first conductive pattern surrounding the first semiconductor pattern, the first conductive pattern being a gate electrode; a first impurity region under the first semiconductor pattern, the first impurity region contacting the first semiconductor pattern, the first impurity region being a source or drain region; and a second impurity region contacting the first semiconductor pattern, the second impurity region being the other of the source or drain region; and a second structure including: second semiconductor patterns spaced apart from each other, each of the second semiconductor patterns protruding from the substrate; second conductive patterns surrounding the second semiconductor patterns, respectively; and first contact plugs connected to the second conductive patterns, wherein the first structure is a vfet, and the second structure includes a resistor or a capacitor.