A semiconductor device and a method of forming the same are provided. In an embodiment, an exemplary semiconductor device 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, and a source/drain feature disposed over the substrate and coupled to the vertical stack of channel members. The source/drain feature is spaced apart from a sidewall of the gate structure by an air gap and a dielectric layer, and the air gap extends into the source/drain feature.

Disclosed are a semiconductor device and a method of fabricating the same. The semiconductor device includes an active pattern on a substrate, a device isolation layer provided on the substrate to define the active pattern, a pair of source/drain patterns on the active pattern and a channel pattern therebetween, the channel pattern including semiconductor patterns which are stacked and are spaced apart from each other, a gate electrode crossing the channel pattern, and a gate spacer on a side surface of the gate electrode. The gate spacer located on the device isolation layer includes an upper portion with a first thickness and a lower portion with a second thickness. The second thickness is larger than the first thickness, and the lower portion of the gate spacer is located at a level lower than the uppermost one of the semiconductor patterns.

A semiconductor device includes a substrate including first and second regions, first and second active patterns provided on the first and second regions, respectively, a pair of first source/drain patterns on the first active pattern and a first channel pattern therebetween, a pair of second source/drain patterns on the second active pattern and a second channel pattern therebetween, first and second gate electrodes respectively provided on the first and second channel patterns, and first and second gate insulating layers respectively interposed between the first and second channel patterns and the first and second gate electrodes. Each of the first and second gate insulating layers includes an interface layer and a first high-k dielectric layer thereon, and the first gate insulating layer further includes a second high-k dielectric layer on the first high-k dielectric layer.

Heterostructures include a layer of a two-dimensional material placed on a multiferroic layer. An ordered array of differing polarization domains in the multiferroic layer produces corresponding domains having differing properties in the two-dimensional material. When the multiferroic layer is ferroelectric, the ferroelectric polarization domains in the layer produce local electric fields that penetrate the two-dimensional material. The local electric fields modulate the charge carriers and carrier density on a nanometer length scale, resulting in the formation of lateral p-n or p-i-n junctions, and variations thereof appropriate for device functions.

A semiconductor device includes first transistor having a first gate stack and first source/drain regions on opposing sides of the first gate stack; a second transistor having a second gate stack and second source/drain regions on opposing sides of the second gate stack; and a gate isolation structure separating the first gate stack from the second gate stack. The gate isolation structure includes a dielectric liner having a varied thickness along sidewalls of the first gate stack and the second gate stack and a dielectric fill material over the dielectric liner, wherein the dielectric fill material comprises a seam.

A semiconductor device includes a substrate having a first side and a second side. The semiconductor device on the first side includes: an active region that extends along a first lateral direction and comprises a first sub-region and a second sub-region; a first gate structure that extends along a second lateral direction and is disposed over the active region, with the first and second sub-regions disposed on opposite sides of the first gate structure, wherein the second lateral direction is perpendicular to the first lateral direction; and a first interconnecting structure electrically coupled to the first gate structure. The semiconductor device on the second side includes a second interconnecting structure that is electrically coupled to the first and second sub-regions and configured to provide a power supply. The active region, the first gate structure, the first interconnecting structure, and the second interconnecting structure are collectively configured as a decoupling capacitor.

A semiconductor device includes a plurality of semiconductor layers vertically separated from one another. The semiconductor device includes a gate structure that comprises a lower portion and an upper portion. The lower portion wraps around each of the plurality of semiconductor layers. The semiconductor device includes a gate spacer that extends along a sidewall of the upper portion of the gate structure and comprises a first layer and a second layer. The first layer is in contact with a first portion of the sidewall and the second layer is in contact with a second portion of the sidewall.

A semiconductor device and related method for forming a gate structure. In some embodiments, a semiconductor device includes a fin extending from a substrate. In some cases, the fin includes a plurality of semiconductor channel layers. In some examples, the semiconductor device further includes a gate dielectric surrounding each of the plurality of semiconductor channel layers. In some embodiments, a first thickness of the gate dielectric disposed on a top surface of a topmost semiconductor channel layer of the plurality of semiconductor channel layers is greater than a second thickness of the gate dielectric disposed on a surface of another semiconductor channel layer disposed beneath the topmost semiconductor channel layer.

A semiconductor device with different configurations of contact structures and a method of fabricating the same are disclosed. The method includes forming first and second fin structures on a substrate, forming n- and p-type source/drain (S/D) regions on the first and second fin structures, respectively, forming first and second contact openings on the n- and p-type S/D regions, respectively, forming a carbon-based layer in the first and second contact openings, performing a remote plasma treatment with radicals on the carbon-based layer to form a remote plasma treated layer, selectively removing a portion of the remote plasma treated layer, forming a p-type work function metal (pWFM) silicide layer on the p-type S/D region, and forming an n-type work function metal (nWFM) silicide layer on the pWFM silicide layer and on the n-type S/D region.

A semiconductor device includes a semiconductor feature, a low-k dielectric feature that is formed on the semiconductor feature, and a Si-containing layer that contains elements of silicon and that covers over the low-k dielectric feature. The Si-containing layer can prevent the low-k dielectric feature from being damaged in etch and/or annealing processes for manufacturing the semiconductor device.