A method for forming a semiconductor structure includes the following steps. A semiconductor device is formed over a substrate. A trench is formed in the semiconductor device. The trench is filled with a gap-fill material using a deposition process, wherein a precursor used in the deposition process includes azidosilane, di-azidosilane or halide azidosilane.

Methods of forming a low-resistance source/drain feature for a multi-gate device are provided. A example method includes forming a fin-shaped structure that includes a plurality of channel layers interleaved by a plurality of sacrificial layers, recessing a source/drain region of the fin-shaped structure to form a source/drain recess, selectively and partially recessing sidewalls of the plurality of sacrificial layers to form inner spacer recesses, forming inner spacers in the inner spacer recesses, forming a bottom dielectric layer over the substrate, depositing a first epitaxial layer over the inner spacers and the sidewalls of the plurality of the channel layers, performing a thermal treatment to reshape the first epitaxial layer, after the performing of the thermal treatment, depositing a second epitaxial layer over the first epitaxial layer. The first epitaxial layer includes germanium and the second epitaxial layer is free of germanium.

A semiconductor structure and a method of forming the same are provided. In an embodiment, an exemplary method includes forming a fin-shaped active region over a substrate and comprising a number of channel layers interleaved by a number of sacrificial layers, removing a source/drain region of the fin-shaped active region to form a source/drain opening, forming a source/drain feature in the source/drain opening, selectively removing the number of sacrificial layers to form a number of gate openings, and forming a gate structure in the number of gate openings, where the gate structure includes a first portion formed in a first gate opening of the number of gate openings and a second portion formed in a second gate opening of the number of gate openings, a gate length of the first portion is different from a gate length of the second portion.

Embodiments of the present disclosure provide a semiconductor device structure and methods of forming the same. The structure includes a source/drain region disposed over a substrate, an interlayer dielectric layer disposed over the source/drain region, a first conductive feature disposed over the source/drain region, a gate electrode layer disposed over the substrate, and a dielectric layer surrounding the first conductive feature. The dielectric layer includes a first portion disposed between the interlayer dielectric layer and the first conductive feature and a second portion disposed between the first conductive feature and the gate electrode layer, at least a portion of the first portion has a first thickness, and the second portion has a second thickness substantially greater than the first thickness.

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.

In some embodiments, the present disclosure relates to an integrated chip that includes a channel structure extending between a first source/drain region and a second source/drain region. Further, a gate electrode is arranged directly over the channel structures, and an upper interconnect contact is arranged over and coupled to the gate electrode. A backside contact is arranged below and coupled to the first source/drain region. The backside contact has a width that decreases from a bottommost surface of the backside contact to a topmost surface of the backside contact.

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 first and a second gate dielectric on a first semiconductor channel region and a second semiconductor channel region overlapping the first semiconductor region, forming a first dipole film on the first gate dielectric, wherein the first dipole film comprises a first dipole dopant of a first type, and forming a second dipole film on the second gate dielectric. A drive-in process is performed to drive dipole dopants in the first dipole film and the second dipole film into the first gate dielectric and the second gate dielectric, respectively. The first dipole film and the second dipole film are removed. A gate electrode is formed on both of the first gate dielectric and the second gate dielectric to form a first transistor and a second transistor.

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.