Abstract: Semiconductor structures and methods of forming the same are provided. In an embodiment, an exemplary semiconductor structure includes a vertical stack of channel members disposed over a substrate, a gate structure wrapping around each channel member of the vertical stack of channel members, a dielectric feature disposed directly on the substrate and in direct contact with a portion of the vertical stack of channel members, and a source/drain feature disposed directly on the dielectric feature and electrically coupled to a remaining portion of the vertical stack of channel members.

Abstract: A method for forming a semiconductor device structure includes forming nanostructures over a substrate. The method also includes forming a work function layer surrounding the nanostructures. The method also includes forming spacers over opposite sides of the work function layer. The method also includes forming a first metal layer over the work function layer and sidewalls of the spacers. The method also includes forming a second metal layer surrounded by the first metal layer. The method also includes etching the first metal layer over opposite sides of the second metal layer. The method also includes forming a cap layer over a top surface and a sidewall of the second metal layer.