A semiconductor device is provided. The semiconductor device includes a substrate including an active pattern, a gate electrode extending in a first direction and crossing the active pattern which extends in a second direction, a separation structure crossing the active pattern and extending in the first direction, a first gate dielectric pattern disposed on a side surface of the gate electrode, a second gate dielectric pattern disposed on a side surface of the separation structure, and a gate capping pattern covering a top surface of the gate electrode. A level of a top surface of the separation structure is higher than a level of a top surface of the gate capping pattern.

Inner spacers between a source/drain region of a nanostructure transistor and sacrificial nanostructure layers of the nanostructure transistor are removed prior to formation of a gate structure of the nanostructure transistor. The sacrificial nanostructure layers are removed, and then the inner spacers are removed. The sacrificial nanostructure layers are then replaced with the gate structure of the nanostructure transistor such that the gate structure and the source/drain region are spaced apart by air gaps that result from the removal of the inner spacers. The dielectric constant (or relative permittivity) of the air gaps between the source/drain region and the gate structure is less than the dielectric constant of the material of the inner spacers. The lesser dielectric constant of the air gaps reduces the amount of capacitance between the source/drain region and the gate structure.

In an embodiment, a semiconductor device may include a plurality of first nanostructures. The plurality of first nanostructures extend between first source/drain regions. The semiconductor device may also include a plurality of second nanostructures over the plurality of first nanostructures. The plurality of second nanostructures extend between second source/drain regions. The device may furthermore include a first gate stack around the plurality of first nanostructures. The device may in addition include a second gate stack over the first gate stack and disposed around the plurality of second nanostructures. The device may moreover include a vertical interconnect structure extending through the first and second gate stacks. The device may also include a frontside contact electrically coupled to a frontside of the vertical interconnect structure and a backside contact electrically coupled to a backside of the vertical interconnect structure.

A semiconductor device includes a first power supply line, a second power supply line, a first ground line, a switch circuit connected to the first and the second power supply line, and a switch control circuit connected to the first ground line and the first power supply line. The switch circuit includes a first and a second transistor of a first conductive type. A first gate electrode of the first transistor is connected to a second gate electrode of the second transistor. The switch control circuit includes a third transistor of a second conductive type, and a fourth transistor of a third conductive type. A third gate electrode of the third transistor is connected to a fourth gate electrode of the fourth transistor. A semiconductor device includes a signal line that electrically connects a connection point between the third and fourth transistor to the first and second gate electrode.

A semiconductor device includes a first power supply line, a second power supply line, a first ground line, a switch circuit connected to the first and the second power supply line, and a switch control circuit connected to the first ground line and the first power supply line. The switch circuit includes a first and a second transistor of a first conductive type. A first gate electrode of the first transistor is connected to a second gate electrode of the second transistor. The switch control circuit includes a third transistor of a second conductive type, and a fourth transistor of a third conductive type. A third gate electrode of the third transistor is connected to a fourth gate electrode of the fourth transistor. A semiconductor device includes a signal line that electrically connects a connection point between the third and fourth transistor to the first and second gate electrode.

A method includes forming a lower semiconductor region, forming an upper semiconductor region overlapping the lower semiconductor region, forming a lower gate dielectric and an upper gate dielectric on the lower semiconductor region and the upper semiconductor region, respectively, forming a lower gate electrode on the lower gate dielectric and the upper gate dielectric, etching back the lower gate electrode, forming a gate isolation layer on the lower gate electrode that has been etched back, and forming an upper gate electrode over the gate isolation layer. The upper gate electrode is on the upper gate dielectric.

The present disclosure relates to semiconductor devices and fabrication methods thereof. An example semiconductor device includes conductive layers. The conductive layers include a first conductive layer and a second conductive layer. The semiconductor device further includes an insulating structure over the first conductive layer and the second conductive layer. The insulating structure includes a first layer. A material of the first layer has a first etching rate smaller than an etching rate of an insulating material between the conductive layers. The semiconductor device further includes a first contact structure extending through a first portion of the first layer and connected to the first conductive layer. The semiconductor device further includes a second contact structure extending through a second portion of the first layer and connected to the second conductive layer.

A method includes forming a first bottom-tier transistor; forming a second bottom-tier transistor, the first and second bottom-tier transistors sharing a same source/drain region; forming a first top-tier transistor over the first bottom-tier transistor, the first top-tier transistor comprising a first channel layer and a first gate structure around the first channel layer; forming a second top-tier transistor over the second bottom-tier transistor, the second top-tier transistor comprising a second channel layer and a second gate structure around the second channel layer, the first and second top-tier transistors sharing a same source/drain region, wherein from a top view, a first dimension of the first channel layer in a lengthwise direction of the first gate structure is different than a second dimension of the second channel layer in the lengthwise direction of the first gate structure.

Integrated circuit structures having differential epitaxial source or drain dent are described. For example, an integrated circuit structure includes a first sub-fin structure beneath a first stack of nanowires or fin. A second sub-fin structure is beneath a second stack of nanowires or fin. A first epitaxial source or drain structure is at an end of the first stack of nanowires of fin, the first epitaxial source or drain structure having no dent or a shallower dent therein. A second epitaxial source or drain structure is at an end of the second stack of nanowires or fin, the second epitaxial source or drain structure having a deeper dent therein.

An integrated circuit (IC) device includes a stripe of material perpendicular to, and spanning between, semiconductor structures with multiple widths, and the stripe is between transistors with channel regions of differing widths in the semiconductor structures. The material stripes cover transition portions between different widths of the semiconductor structures. The semiconductor structures may be channel structures of different types, including groups of fins or nanoribbons. Channel regions of differing widths may include more or fewer fins or narrower or wider nanoribbons. The channel regions may have alternating conductivity types, n- and p-type.