The present disclosure provides a semiconductor structure that includes a substrate having a frontside and a backside; an active region extruded from the substrate and surrounded by an isolation feature; a gate stack formed on the front side of the substrate and disposed on the active region; a first and a second source/drain (S/D) feature formed on the active region and interposed by the gate stack; a frontside contact feature disposed on a top surface of the first S/D feature; a backside contact feature disposed on and electrically connected to a bottom surface of the second S/D feature; and a semiconductor layer disposed on a bottom surface of the first S/D feature with a first thickness and a bottom surface of the gate stack with a second thickness being greater than the first thickness.

Various embodiments of the present disclosure are directed towards a semiconductor device including a gate electrode over a semiconductor substrate. An epitaxial source/drain layer is disposed on the semiconductor substrate and is laterally adjacent to the gate electrode. The epitaxial source/drain layer comprises a first dopant. A diffusion barrier layer is between the epitaxial source/drain layer and the semiconductor substrate. The diffusion barrier layer comprises a barrier dopant that is different from the first dopant.

A device includes a substrate, an isolation structure over the substrate, and two fins extending from the substrate and above the isolation structure. Two source/drain structures are over the two fins respectively and being side by side along a first direction generally perpendicular to a lengthwise direction of the two fins from a top view . Each of the two source/drain structures has a near-vertical side, the two near-vertical sides facing each other along the first direction. A contact etch stop layer (CESL) is disposed on at least a lower portion of the near-vertical side of each of the two source/drain structures. And two contacts are disposed over the two source/drain structures, respectively, and over the CESL.

A method to form a transistor device with a recessed gate structure is provided. In one embodiment, a gate structure is formed overlying a device region and an isolation structure. The gate structure separates a device doping well along a first direction with a pair of recess regions disposed on opposite sides of the device region in a second direction perpendicular to the first direction. A pair of source/drain regions in is formed the device region on opposite sides of the gate structure. A sidewall spacer is formed extending along sidewalls of the gate structure, where a top surface of the sidewall spacer is substantially flush with the top surface of the gate structure. A resistive protection layer is then formed on the sidewall spacer and covering the pair of recess regions.

A semiconductor device may include a first device on a first portion of a substrate, a second device on a second portion of the substrate, and a third device on a third portion of the substrate. The third device may include an oxide layer that is formed from an oxide layer that is a sacrificial oxide layer for the first device and the second device. The third device may include a gate provided on the oxide layer, a set of spacers provided on opposite sides of the gate, and a source region provided in the third portion of the substrate on one side of the gate. The third device may include a drain region provided in the third portion of the substrate on another side of the gate, and a protective oxide layer provided on a portion of the gate and a portion of the drain region.

A semiconductor device structure includes nanostructures formed over a substrate. The structure also includes a gate structure formed over and around the nanostructures. The structure also includes a spacer layer formed over a sidewall of the gate structure over the nanostructures. The structure also includes a source/drain epitaxial structure formed adjacent to the spacer layer. The structure also includes a contact structure formed over the source/drain epitaxial structure with an air spacer formed between the spacer layer and the contact structure.

A semiconductor device includes a substrate, two source/drain features over the substrate, channel layers connecting the two source/drain features, and a gate structure wrapping around each of the channel layers. Each of the two source/drain features include a first epitaxial layer, a second epitaxial layer over the first epitaxial layer, and a third epitaxial layer on inner surfaces of the second epitaxial layer. The channel layers directly interface with the second epitaxial layers and are separated from the third epitaxial layers by the second epitaxial layers. The first epitaxial layers include a first semiconductor material with a first dopant. The second epitaxial layers include the first semiconductor material with a second dopant. The second dopant has a higher mobility than the first dopant.

A semiconductor structure and a method for forming a semiconductor structure are provided. The semiconductor structure includes a substrate; a doped region within the substrate; a pair of source/drain regions extending along a first direction on opposite sides of the doped region; a gate electrode disposed in the doped region, wherein the gate electrode has a plurality of first segments extending in parallel along the first direction; and a protection structure over the substrate and at least partially overlaps the gate electrode.

A semiconductor structure and a method for forming a semiconductor structure are provided. The semiconductor structure includes a substrate; a gate electrode disposed within the substrate; a gate dielectric layer disposed within the substrate and surrounding the gate electrode; a plurality of first protection structures disposed over the gate electrode; a second protection structure disposed over the gate dielectric layer; and a pair of source/drain regions on opposing sides of the gate dielectric layer.

The present disclosure relates to a semiconductor device and a method for forming a semiconductor device with a graphene conductive structure. The semiconductor device includes a first gate structure disposed over a semiconductor substrate, and a first source/drain region disposed in the semiconductor substrate and adjacent to the first gate structure. The semiconductor device also includes a first silicide layer disposed in the semiconductor substrate and over the first source/drain region, and a graphene conductive structure disposed over the first silicide layer. The semiconductor device further includes a first dielectric layer covering the first gate structure, and a second dielectric layer disposed over the first dielectric layer. The graphene conductive structure is surrounded by the first dielectric layer and the second dielectric layer.