A semiconductor device includes active fins extending in a first direction on a substrate; an isolation insulating layer covering a portion of side surfaces of the active fins; channel layers stacked vertically and spaced apart on the active fins; a gate pattern in a second direction across the active fins and the channel layers; and spacer layers across the active fins in the second direction on both sides of the gate pattern. At least one spacer layer extends downwardly along a side surface of the gate pattern such that a lower surface thereof contacts the isolation insulating layer. The lower surface of the spacer layer is higher than a level of upper surfaces of the active fins. The gate pattern has a lower surface contacting the isolation insulating layer. The lower surface of the gate pattern is lower than a level of the upper surfaces of the active fins.

In a semiconductor structure, a first conductive feature is formed in a trench by PVD and a glue layer is then deposited on the first conductive feature in the trench before CVD deposition of a second conductive feature there-over. The first conductive feature acts as a protection layer to keep silicide from being damaged by later deposition of metal or a precursor by CVD. The glue layer extends along the extent of the sidewall to enhance the adhesion of the second conductive features to the surrounding dielectric layer.

A semiconductor device according to an embodiment includes: a silicon carbide layer; a metal layer; and a conductive layer positioned between the silicon carbide layer and the metal layer, the conductive layer containing a silicide of one metal element (M) selected from the group consisting of nickel (Ni), palladium (Pd), and platinum (Pt), and the conductive layer having a carbon concentration of 1×10.sup.17 cm.sup.−3 or less.

A semiconductor structure and a method of forming the same are provided. In an embodiment, a semiconductor structure includes an epitaxial source feature and an epitaxial drain feature, a vertical stack of channel members disposed over a backside dielectric layer, the vertical stack of channel members extending between the epitaxial source feature and the epitaxial drain feature along a direction, a gate structure wrapping around each of the vertical stack of channel members, and a backside source contact disposed in the backside dielectric layer. The backside source contact includes a top portion adjacent the epitaxial source feature and a bottom portion away from the epitaxial source feature. The top portion and the bottom portion includes a step width change along the direction.

An apparatus comprises a first metal feature in a first dielectric layer over a substrate, wherein a sidewall portion of the first dielectric layer is over a top surface of the first metal feature, a second dielectric layer over the first dielectric layer and a second metal feature extending through the second dielectric layer, wherein a bottom of a first portion of the second metal feature is in contact with the top surface of the first metal feature and a bottom of a second portion of the second metal feature is in contact with the sidewall portion of the first dielectric layer.

A chip structure includes a substrate, a bottom conductive layer, a semiconductor layer, an interlayer dielectric layer, at least one electrode, and at least one top electrode. The substrate includes in order a core layer and a composite material. The bottom conductive layer is disposed on the bottom surface of the core layer, the semiconductor layer is disposed on the substrate, and an interlayer dielectric layer is disposed on the semiconductor layer. The at least one electrode is disposed between the semiconductor layer and the interlayer dielectric layer, and the at least one top electrode is disposed on the interlayer dielectric layer and electrically coupled to the at least one electrode.

A device includes a fin extending from a semiconductor substrate; a gate stack over the fin; a first spacer on a sidewall of the gate stack; a source/drain region in the fin adjacent the first spacer; an inter-layer dielectric layer (ILD) extending over the gate stack, the first spacer, and the source/drain region, the ILD having a first portion and a second portion, wherein the second portion of the ILD is closer to the gate stack than the first portion of the ILD; a contact plug extending through the ILD and contacting the source/drain region; a second spacer on a sidewall of the contact plug; and an air gap between the first spacer and the second spacer, wherein the first portion of the ILD extends across the air gap and physically contacts the second spacer, wherein the first portion of the ILD seals the air gap.

A source/drain is disposed over a substrate. A source/drain contact is disposed over the source/drain. A first via is disposed over the source/drain contact. The first via has a laterally-protruding bottom portion and a top portion that is disposed over the laterally-protruding bottom portion.

In an embodiment, a device includes: a first fin; a gate structure over the first fin; a first source/drain region adjacent the gate structure; an etch stop layer over the first source/drain region; a conductive line over the etch stop layer, the conductive line isolated from the first source/drain region by the etch stop layer, a top surface of the conductive line being coplanar with a top surface of the gate structure; and a power rail contact extending through the first fin, the power rail contact connected to the first source/drain region.

An integrated circuit structure includes a substrate, a transistor, a first dielectric layer, a metal contact, a first low-k dielectric layer, a second dielectric layer, and a first metal feature. The transistor is over the substrate. The first dielectric layer is over the transistor. The metal contact is in the first dielectric layer and electrically connected to the transistor. The first low-k dielectric layer is over the first dielectric layer. The second dielectric layer is over the first low-k dielectric layer and has a dielectric constant higher than a dielectric constant of the first low-k dielectric layer. The first metal feature extends through both second dielectric layer and the first low-k dielectric layer to the metal contact.