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.

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 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 method of forming a semiconductor device includes forming a fin extending from a substrate. The fin has a source/drain (S/D) region and a channel region. The fin includes a first semiconductor layer and a second semiconductor layer on the first semiconductor layer. The first semiconductor layer has a first composition, and the second semiconductor layer has a second composition different from the first composition. The method further includes removing the first semiconductor layer from the S/D region of the fin such that a first portion of the second semiconductor layer in the S/D region is suspended in a space. The method further includes epitaxially growing a third semiconductor layer in the S/D region, the third semiconductor layer wrapping around the first portion of the second semiconductor layer.

Abstract: Disclosed are methods to form a FinFET diode of high efficiency, designed to resolve the degradation problem with a conventional FinFET diode arising from reduced active area, and a method of fabrication. The FinFET diode has a doped substrate, two spaced-apart groups of semiconductor fin structures, dielectric layers formed between the two groups and among the fin structures for insulation, a plurality of gate structures perpendicularly traversing both groups of the fin structures, and two groups of semiconductor strips respectively formed lengthwise upon the two groups of the fin structures. The two groups of semiconductor strips are doped to have opposite conductivity types, p-type and n-type. In an embodiment, the FinFET diode further has metal contacts formed upon the semiconductor strips. In another embodiment, the semiconductor strips may be integrally formed with the fin structures by epitaxial growth and in-situ doped.

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 device includes a substrate having a fin structure, the fin structure having a height in a substantially perpendicular direction to the substrate, and having consecutive upper and lower portions along the height, the lower portion being closer to the substrate than the upper portion. The semiconductor device further includes a gate structure wrapping around a portion of the fin structure, the gate structure having a gate dielectric layer disposed around the fin structure, and a gate electrode layer disposed over the gate dielectric layer. The gate electrode layer includes a first gate metal layer formed along both sides of the lower portion of the fin structure, the first gate metal layer having a first workfunction, and a second gate metal layer formed disposed over the first gate metal layer and wrapped around the upper portion of the fin structure, the second gate metal layer having a second workfunction. The first and the second workfunctions are different.

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 method of forming a semiconductor device includes forming a fin extending from a substrate. The fin has a source/drain (S/D) region and a channel region. The fin includes a first semiconductor layer and a second semiconductor layer on the first semiconductor layer. The first semiconductor layer has a first composition, and the second semiconductor layer has a second composition different from the first composition. The method further includes removing the first semiconductor layer from the S/D region of the fin such that a first portion of the second semiconductor layer in the S/D region is suspended in a space. The method further includes epitaxially growing a third semiconductor layer in the S/D region, the third semiconductor layer wrapping around the first portion of the second semiconductor layer.

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: 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 series-connected transistor structure includes a first source, a first channel-drain structure, a second channel-drain structure, a gate dielectric layer, a gate, a first drain pad and a second drain pad. The first source is over a substrate. The first channel-drain structure is over the first source and includes a first channel and a first drain thereover. The second channel-drain structure is over the first source and substantially parallel to the first channel-drain structure and includes a second channel and a second drain thereover. The gate dielectric layer surrounds the first channel and the second channel. The gate surrounds the gate dielectric layer. The first drain pad is over and in contact with the first drain. The second drain pad is over and in contact with the second drain, in which the first drain pad and the second drain pad are separated from each other.