Abstract: A semiconductor includes a first transistor and a second transistor. The first transistor includes a first and a second epitaxial layer, formed of a first semiconductor material. The second epitaxial layer is disposed over the first epitaxial layer. The first transistor also includes a first gate dielectric layer surrounds the first and second epitaxial layers and extends from a top surface of the first epitaxial layer to a bottom surface of the second epitaxial layer and a first metal gate layer surrounding the first gate dielectric layer. The second transistor includes a third epitaxial layer formed of the first semiconductor material and a fourth epitaxial layer disposed directly on the third epitaxial layer and formed of a second semiconductor. The second transistor also includes a second gate dielectric layer disposed over the third and fourth epitaxial layers and a second metal gate layer disposed over the second gate dielectric layer.

Abstract: Various transistors, such as horizontal gate-all-around transistors, and methods of fabricating such are disclosed herein. An exemplary transistor includes a first nanowire and a second nanowire that include a first semiconductor material, a gate that wraps a channel region of the first nanowire and the second nanowire, and source/drain feature that wraps source/drain regions of the first nanowire and the second nanowire. The source/drain feature includes a second semiconductor material that is configured differently than the first semiconductor material. In some implementations, the transistor further includes a fin-like semiconductor layer disposed over a substrate. The first nanowire and the second nanowire are disposed over the fin-like semiconductor layer, such that the first nanowire, the second nanowire, and the fin-like semiconductor layer extend substantially parallel to one another along the same length-wise direction.

Abstract: A semiconductor device includes a channel region, a source/drain region adjacent to the channel region, and a source/drain epitaxial layer. The source/drain epitaxial layer includes a first epitaxial layer epitaxially formed on the source/drain region, a second epitaxial layer epitaxially formed on the first epitaxial layer and a third epitaxial layer epitaxially formed on the second epitaxial layer. The first epitaxial layer includes at least one selected from the group consisting of a SiAs layer, a SiC layer and a SiCP layer.

Abstract: A method of manufacturing a semiconductor device, a plurality of fin structures are formed over a semiconductor substrate. The fin structures extend along a first direction and are arranged in a second direction crossing the first direction. A plurality of sacrificial gate structures extending in the second direction are formed over the fin structures. An interlayer dielectric layer is formed over the plurality of fin structures between adjacent sacrificial gate structures. The sacrificial gate structures are cut into a plurality of pieces of sacrificial gate structures by forming gate end spaces along the second direction. Gate separation plugs are formed by filling the gate end spaces with two or more dielectric materials. The two or more dielectric materials includes a first layer and a second layer formed on the first layer, and a dielectric constant of the second layer is smaller than a dielectric constant of the first layer.

Abstract: A semiconductor structure includes a plurality of first semiconductor layers interleaved with a plurality of second semiconductor layers. The first and second semiconductor layers have different material compositions. A dummy gate stack is formed over an uppermost first semiconductor layer. A first etching process is performed to remove portions of the second semiconductor layer that are not disposed below the dummy gate stack, thereby forming a plurality of voids. The first etching process has an etching selectivity between the first semiconductor layer and the second semiconductor layer. Thereafter, a second etching process is performed to enlarge the voids.

Abstract: A method of generating a netlist of an IC device includes extracting dimensions of a gate region of the IC device, the dimensions including a width of the gate region, the width extending at least from a first edge of an active region to a second edge of the active region, and a distance from a first end of the width to a gate via positioned along the width. A first gate resistance value corresponding to the gate region is received, a second gate resistance value is determined based on the distance and the width, and the netlist is updated based on the first and second gate resistance values.

Abstract: A semiconductor structure includes a plurality of first semiconductor layers interleaved with a plurality of second semiconductor layers. The first and second semiconductor layers have different material compositions. A dummy gate stack is formed over an uppermost first semiconductor layer. A first etching process is performed to remove portions of the second semiconductor layer that are not disposed below the dummy gate stack, thereby forming a plurality of voids. The first etching process has an etching selectivity between the first semiconductor layer and the second semiconductor layer. Thereafter, a second etching process is performed to enlarge the voids.

Abstract: A semiconductor device includes a substrate, a first source/drain (S/D) region, a second S/D region, and a semiconductor sheet. The first S/D region is disposed on the substrate. The second S/D region is disposed above the first S/D region. The semiconductor sheet interconnects the first and second S/D regions and includes a plurality of turns. A method for fabricating the semiconductor device is also disclosed.

Abstract: A semiconductor structure includes a plurality of first semiconductor layers interleaved with a plurality of second semiconductor layers. The first and second semiconductor layers have different material compositions. A dummy gate stack is formed over an uppermost first semiconductor layer. A first etching process is performed to remove portions of the second semiconductor layer that are not disposed below the dummy gate stack, thereby forming a plurality of voids. The first etching process has an etching selectivity between the first semiconductor layer and the second semiconductor layer. Thereafter, a second etching process is performed to enlarge the voids.

Abstract: A semiconductor device includes a substrate, a bottom semiconductor fin, at least one sidewall structure, a top semiconductor fin, and a gate structure. The bottom semiconductor fin is disposed on the substrate. The sidewall structure protrudes from the semiconductor fin. The top semiconductor fin is disposed on the bottom semiconductor fin. The top semiconductor fin includes a channel portion and at least one source/drain portion. The source/drain portion is disposed between the channel portion and the sidewall structure. The gate structure covers the channel portion of the top semiconductor fin.

Abstract: A semiconductor device includes a substrate, a bottom semiconductor fin, at least one sidewall structure, a top semiconductor fin, and a gate structure. The bottom semiconductor fin is disposed on the substrate. The sidewall structure protrudes from the semiconductor fin. The top semiconductor fin is disposed on the bottom semiconductor fin. The top semiconductor fin includes a channel portion and at least one source/drain portion. The source/drain portion is disposed between the channel portion and the sidewall structure. The gate structure covers the channel portion of the top semiconductor fin.

Abstract: Various transistors, such as horizontal gate-all-around transistors, and methods of fabricating such are disclosed herein. An exemplary transistor includes a first nanowire and a second nanowire that include a first semiconductor material, a gate that wraps a channel region of the first nanowire and the second nanowire, and source/drain feature that wraps source/drain regions of the first nanowire and the second nanowire. The source/drain feature includes a second semiconductor material that is configured differently than the first semiconductor material. In some implementations, the transistor further includes a fin-like semiconductor layer disposed over a substrate. The first nanowire and the second nanowire are disposed over the fin-like semiconductor layer, such that the first nanowire, the second nanowire, and the fin-like semiconductor layer extend substantially parallel to one another along the same length-wise direction.

Abstract: A semiconductor structure includes a plurality of first semiconductor layers interleaved with a plurality of second semiconductor layers. The first and second semiconductor layers have different material compositions. A dummy gate stack is formed over an uppermost first semiconductor layer. A first etching process is performed to remove portions of the second semiconductor layer that are not disposed below the dummy gate stack, thereby forming a plurality of voids. The first etching process has an etching selectivity between the first semiconductor layer and the second semiconductor layer. Thereafter, a second etching process is performed to enlarge the voids.

Abstract: Various semiconductor devices, such as horizontal gate-all-around devices, and methods of fabricating such are disclosed herein. An exemplary semiconductor device includes a fin structure having a channel region disposed between a first source/drain region and a second source/drain region. The fin structure includes a first nanowire and a second nanowire disposed in the channel region, the first source/drain region, and the second source/drain region. The fin structure further includes an epitaxial layer that wraps the first nanowire and the second nanowire in the first source/drain region and the second source/drain region. A gate is disposed over the channel region of the fin structure, such that the gate wraps the first nanowire and the second nanowire in the channel region. In some implementations, the first nanowire, the second nanowire, and the epitaxial layer combine to have a vertical bar-like shape in the first source/drain region and the second source/drain region.

Abstract: A semiconductor includes a first transistor and a second transistor. The first transistor includes a first and a second epitaxial layer, formed of a first semiconductor material. The second epitaxial layer is disposed over the first epitaxial layer. The first transistor also includes a first gate dielectric layer surrounds the first and second epitaxial layers and extends from a top surface of the first epitaxial layer to a bottom surface of the second epitaxial layer and a first metal gate layer surrounding the first gate dielectric layer. The second transistor includes a third epitaxial layer formed of the first semiconductor material and a fourth epitaxial layer disposed directly on the third epitaxial layer and formed of a second semiconductor. The second transistor also includes a second gate dielectric layer disposed over the third and fourth epitaxial layers and a second metal gate layer disposed over the second gate dielectric layer.

Abstract: A semiconductor device includes a source/drain feature disposed over a substrate. The source/drain feature includes a first nanowire, a second nanowire disposed over the first nanowire, a cladding layer disposed over the first nanowire and the second nanowire and a spacer layer extending from the first nanowire to the second nanowire. The device also includes a conductive feature disposed directly on the source/drain feature such that the conductive feature physically contacts the cladding layer and the spacer layer.

Abstract: A semiconductor structure includes a plurality of first semiconductor layers interleaved with a plurality of second semiconductor layers. The first and second semiconductor layers have different material compositions. A dummy gate stack is formed over an uppermost first semiconductor layer. A first etching process is performed to remove portions of the second semiconductor layer that are not disposed below the dummy gate stack, thereby forming a plurality of voids. The first etching process has an etching selectivity between the first semiconductor layer and the second semiconductor layer. Thereafter, a second etching process is performed to enlarge the voids.

Abstract: The present disclosure provides a semiconductor structure. The semiconductor structure includes a substrate having a first region and a second region; a first fin feature formed on the substrate within the first region; and a second fin feature formed on the substrate within the second region. The first fin feature includes a first semiconductor feature of a first semiconductor material formed on a dielectric feature that is an oxide of a second semiconductor material. The second fin feature includes a second semiconductor feature of the first semiconductor material formed on a third semiconductor feature of the second semiconductor material.

Abstract: A semiconductor includes a first transistor and a second transistor. The first transistor includes a first and a second epitaxial layer, formed of a first semiconductor material. The second epitaxial layer is disposed over the first epitaxial layer. The first transistor also includes a first gate dielectric layer surrounds the first and second epitaxial layers and extends from a top surface of the first epitaxial layer to a bottom surface of the second epitaxial layer and a first metal gate layer surrounding the first gate dielectric layer. The second transistor includes a third epitaxial layer formed of the first semiconductor material and a fourth epitaxial layer disposed directly on the third epitaxial layer and formed of a second semiconductor. The second transistor also includes a second gate dielectric layer disposed over the third and fourth epitaxial layers and a second metal gate layer disposed over the second gate dielectric layer.

Abstract: A semiconductor device includes a source/drain feature disposed over a substrate. The source/drain feature includes a first nanowire, a second nanowire disposed over the first nanowire, a cladding layer disposed over the first nanowire and the second nanowire and a spacer layer extending from the first nanowire to the second nanowire. The device also includes a conductive feature disposed directly on the source/drain feature such that the conductive feature physically contacts the cladding layer and the spacer layer.