A device a includes a substrate, two source/drain (S/D) features over the substrate, and semiconductor layers suspended over the substrate and connecting the two S/D features. The device further includes a dielectric layer disposed between two adjacent layers of the semiconductor layers and an air gap between the dielectric layer and one of the S/D features, where a ratio between a length of the air gap to a thickness of the first dielectric layer is in a range of 0.1 to 1.0.

A semiconductor device including fin field-effect transistors, includes a first gate structure extending in a first direction, a second gate structure extending the first direction and aligned with the first gate structure in the first direction, a third gate structure extending in the first direction and arranged in parallel with the first gate structure in a second direction crossing the first direction, a fourth gate structure extending the first direction, aligned with the third gate structure and arranged in parallel with the second gate structure, an interlayer dielectric layer disposed between the first to fourth gate electrodes, and a separation wall made of different material than the interlayer dielectric layer and disposed between the first and third gate structures and the second and fourth gate structures.

A method includes providing first and second structures over a substrate, wherein each of the first and second structures includes source/drain (S/D) regions, a channel region between the S/D regions, a sacrificial dielectric layer, and a sacrificial gate. The method further includes partially recessing the sacrificial gate without exposing the sacrificial dielectric layer in each of the first and the second structures; forming a first patterned mask that covers the first structure; removing the sacrificial gate from the second structure; removing the first patterned mask and the sacrificial dielectric layer from the second structure; and depositing a layer of a capacitor material over the portion of the sacrificial gate in the first structure and over the channel region in the second structure.

A semiconductor device is capable of improving the performance and reliability of a device. The semiconductor device includes a first fin-shaped pattern which extends lengthwise in a first direction, a second fin-shaped pattern which is spaced apart from the first fin-shaped pattern in a second direction and extends lengthwise in the first direction, a first gate electrode extending lengthwise in the second direction on the first fin-shaped pattern, a second gate electrode extending lengthwise in the second direction on the second fin-shaped pattern, a first gate separation structure which separates the first gate electrode and the second gate electrode and is at the same vertical level as the first gate electrode and the second gate electrode, and a first source/drain contact extending lengthwise in the second direction on the first fin-shaped pattern and the second fin-shaped pattern. The first source/drain contact includes a first lower source/drain contact region which intersects the first fin-shaped pattern and the second fin-shaped pattern, and a first upper source/drain contact region which protrudes from the first lower source/drain contact region, and the first upper source/drain contact region does not overlap the first gate separation structure in the first direction.

Provided is a semiconductor architecture including a wafer, a semiconductor device provided on the wafer, the semiconductor device including an epitaxial layer, an epitaxial contact provided on the epitaxial layer, a first via provided on the epitaxial contact, and metal lines provided on the first via, the metal lines being configured to route signals, an oxide layer provided on a first surface of the wafer and adjacent to the semiconductor device, and a buried power rail (BPR) configured to deliver power, at least a portion of the BPR being included inside of the wafer, wherein a portion of the BPR contacts the oxide layer.

A multi-stack semiconductor device includes: a substrate; and a plurality of multi-stack transistor structures arranged on the substrate in a channel width direction, wherein the multi-stack transistor structure include at least one lower transistor structure and at least one upper transistor structure stacked above the lower transistor structure, wherein the lower and upper transistor structures include at least one channel layer as a current channel, wherein the lower transistor structures of at least two multi-stack transistor structures have different channel-layer widths.

A method includes forming a semiconductor fin protruding higher than a top surface of an isolation region. The semiconductor fin overlaps a semiconductor strip, and the semiconductor strip contacts the isolation region. The method further includes forming a gate stack on a sidewall and a top surface of a first portion of the semiconductor fin, and etching the semiconductor fin and the semiconductor strip to form a trench. The trench has an upper portion in the semiconductor fin and a lower portion in the semiconductor strip. A semiconductor region is grown in the lower portion of the trench. Process gases used for growing the semiconductor region are free from both of n-type dopant-containing gases and p-type dopant-containing gases. A source/drain region is grown in the upper portion of the trench, wherein the source/drain region includes a p-type or an n-type dopant.

A semiconductor device includes a stack of semiconductor layers vertically arranged above a semiconductor base structure, a gate dielectric layer having portions each surrounding one of the semiconductor layers, and a gate electrode surrounding the gate dielectric layer. Each portion of the gate dielectric layer has a top section above the respective semiconductor layer and a bottom section below the semiconductor layer. The top section has a top thickness along a vertical direction perpendicular to a top surface of the semiconductor base structure; and the bottom section has a bottom thickness along the vertical direction. The top thickness is greater than the bottom thickness.

A vertical field-effect transistor. The vertical field-effect transistor includes: a drift area; a first semiconductor fin on or above the drift area and electrically conductively connected thereto; a plurality of second semiconductor fins on or above the drift area, the plurality of second semiconductor fins being formed connected electrically nonconductively to the drift area, the plurality of second semiconductor fins being situated laterally adjacent to at least one side wall of the first semiconductor fin and being electrically conductively connected thereto; and a source/drain electrode, which is electrically conductively connected to the plurality of second semiconductor fins.

A circuit chip including a substrate, first and second channel active regions on the substrate, and extending in a first direction, the second channel active regions spaced apart from the first channel regions in a second direction intersecting the first direction, first and second gate electrodes intersecting the second channel active regions, third and fourth gate electrodes intersecting the first channel active regions, and a contact electrode between the first, second, third, and fourth gate electrodes. The contact electrode including a stem section in a vertical direction, and first and second branch sections extending from the stem section and contacting a respective source/drain region on the first and second channel active regions, the first gate electrode and the third gate electrode overlapping in the second direction, and including edge portions having widths decreasing as the first gate electrode and the third gate electrode extend toward facing ends thereof.