In an embodiment, an exemplary method includes forming a source/drain opening extending into a substrate, forming a semiconductor layer in a bottom portion of the source/drain opening, forming a dielectric feature in the source/drain opening and on the semiconductor layer, epitaxially growing a source/drain feature in the source/drain opening, wherein the source/drain feature is in direct contact with the dielectric feature, removing the semiconductor layer and a portion of the substrate disposed directly under the semiconductor layer to form a trench, selectively removing the dielectric feature to enlarge the trench, after the selectively removing of the dielectric feature, forming a silicide layer in the enlarged trench, and depositing a conductive layer in the enlarged trench and in direct contact with the silicide layer.

A method of forming a semiconductor device includes: forming a gate structure over a fin; forming an interlayer dielectric (ILD) layer over the fin around the gate structure; forming a first dielectric plug and a second dielectric plug in the gate structure on opposing sides of the fin, where the first and second dielectric plugs cut the gate structure into a plurality of discrete segments; forming a patterned mask layer over the ILD layer, where an opening of the patterned mask layer exposes a segment of the gate structure interposed between the first and second dielectric plugs; etching, using the patterned mask layer as an etching mask, the segment of the gate structure using an isotropic etching process to form a recess in the gate structure; extending the recess into the fin by performing an anisotropic etching process; and after extending the recess, filling the recess with a dielectric material.

Device-level interconnects having high thermal stability for stacked device structures are disclosed herein. An exemplary stacked semiconductor structure includes an upper source/drain contact disposed on an upper epitaxial source/drain, a lower source/drain contact disposed on a lower epitaxial source/drain, and a source/drain via connected to the upper source/drain contact and the lower source/drain contact. The source/drain via is disposed on the upper source/drain contact, the source/drain via extends below the upper source/drain contact, and the source/drain via includes ruthenium and aluminum. In some embodiments, the source/drain via includes a ruthenium plug wrapped by an aluminum liner. In some embodiments, the source/drain via includes a ruthenium aluminide plug. In some embodiments, the source/drain via includes a ruthenium plug wrapped by a ruthenium aluminide liner. In some embodiments, the source/drain via extends below a top of the lower epitaxial source/drain.

A method of forming a semiconductor device includes: forming a device layer that includes nanostructures and a gate structure around the nanostructures; forming a first interconnect structure on a front-side of the device layer; and forming a second interconnect structure on a backside of the device layer, which includes: forming a dielectric layer along the backside of the device layer using a first dielectric material; forming a first conductive feature and a second conductive feature in the dielectric layer; form an opening in the dielectric layer between the first and the second conductive features; forming a first barrier layer and a second barrier layer along a first sidewall of the first conductive feature and along a second sidewall of the second conductive feature, respectively; and forming a second dielectric material different from the first dielectric material in the opening between the first barrier layer and the second barrier layer.

An example semiconductor device includes a lower wiring layer including lower wiring lines, an upper wiring layer including upper wiring lines, and a power gating cell between the lower and upper wiring layers. The power gating cell includes a first active region on a substrate and including first and second lower source/drain patterns and a first channel pattern connecting the first and second lower source/drain patterns with each other, a second active region on the first active region and including first and second upper source/drain patterns, and a power gate electrode surrounding the first channel pattern and extending in a first direction parallel to a top surface of the substrate. The lower wiring layer includes a global power line connected with the first lower source/drain pattern and a local power line connected with the second lower source/drain pattern.

A semiconductor device may include an insulating pattern on a first lower interlayer insulating layer, nanosheets vertically stacked on the insulating pattern, a gate electrode on the insulating pattern and surrounding the nanosheets, a source/drain region on one side of the gate electrode on the insulating pattern, and a source/drain contact electrically connected to the source/drain region. The source/drain region, the first lower interlayer insulating layer, and the insulating pattern may define a contact trench and the source/drain contact may fill the contact trench. The source/drain contact may include a barrier layer, a first filling layer between parts of the barrier layer in the contact trench, and a second filling layer in the contact trench under the first filling layer. The first filling layer may be multi grain and may have a first average grain size. The second filling layer may be single grain.

Embodiments of the present disclosure provide semiconductor device structures and methods of forming the same. The structure includes a first source/drain region disposed under a well portion, a second source/drain region disposed adjacent the first source/drain region, a dielectric material disposed between the first and second source/drain regions, and a conductive contact having a first portion disposed under the first source/drain region and a second portion disposed adjacent the first source/drain region. The second portion is disposed in the dielectric material. The structure further includes a conductive feature disposed in the dielectric material, and the conductive feature is electrically connected to the conductive contact. The conductive feature has a top surface that is substantially coplanar with a top surface of the well portion.

Provided is a semiconductor device including: a channel structure; a gate structure on the channel structure; a backside isolation structure on the gate structure; an alignment spacer layer on a lower side surface of the backside isolation structure, the alignment spacer layer comprising a material different from the backside isolation structure; a source/drain pattern on the channel structure; and a backside contact structure on the source/drain pattern.