A method for fabricating a semiconductor device includes the steps of forming a gate structure on a substrate, forming an interlayer dielectric (ILD) layer on the gate structure, forming a contact hole in the ILD layer adjacent to the gate structure, performing a plasma doping process to form a doped layer in the ILD layer and a source/drain region adjacent to the gate structure, forming a conductive layer in the contact hole, planarizing the conductive layer to form a contact plug, removing the doped layer to form an air gap adjacent to the contact plug, and then forming a stop layer on the ILD layer and the contact plug.

A method for fabricating a semiconductor device includes the steps of forming a gate structure on a substrate, forming an interlayer dielectric (ILD) layer on the gate structure, forming a contact hole in the ILD layer adjacent to the gate structure, performing a plasma doping process to form a doped layer in the ILD layer and a source/drain region adjacent to the gate structure, forming a conductive layer in the contact hole, planarizing the conductive layer to form a contact plug, removing the doped layer to form an air gap adjacent to the contact plug, and then forming a stop layer on the ILD layer and the contact plug.

A semiconductor device includes a gate structure on a substrate, a source/drain region adjacent to the gate structure, an interlayer dielectric (ILD) layer around the gate structure, a contact plug in the ILD layer and adjacent to the gate structure, an air gap around the contact plug, a barrier layer on and sealing the air gap, a metal layer on the barrier layer, a stop layer adjacent to the barrier layer and on the ILD layer, and an inter-metal dielectric (IMD) layer on the ILD layer. Preferably, bottom surfaces of the barrier layer and the stop layer are coplanar and top surfaces of the IMD layer and the barrier layer are coplanar.

Disclosed are methods and systems for providing silicon carbide films. A layer of silicon carbide can be provided under process conditions that employ one or more silicon-containing precursors that have one or more silicon-hydrogen bonds and/or silicon-silicon bonds. The silicon-containing precursors may also have one or more silicon-oxygen bonds and/or silicon-carbon bonds. One or more radical species in a substantially low energy state can react with the silicon-containing precursors to form the silicon carbide film. The one or more radical species can be formed in a remote plasma source.

The present disclosure is directed to method for the fabrication of spacer structures between source/drain epitaxial structures and metal gate structures in nanostructure transistors. The method includes forming a fin structure with alternating first and second nanostructure elements on a substrate. The method also includes etching edge portions of the first nanostructure elements in the fin structure to form spacer cavities, and depositing a spacer layer on the fin structure to fill the spacer cavities. Further, treating the spacer layer with a microwave-generated plasma to form an oxygen concentration gradient within the spacer layer outside the spacer cavities and removing, with an etching process, the treated portion of the spacer layer. During the etching process, a removal rate of the etching process for the treated portion of the spacer layer is based on an oxygen concentration within the oxygen concentration gradient.

A semiconductor device includes a substrate having a semiconductor fin. A gate structure is over the semiconductor fin, in which the gate structure has a tapered profile and comprises a gate dielectric. A work function metal layer is over the gate dielectric, and a filling metal is over the work function metal layer. A gate spacer is along a sidewall of the gate structure, in which the work function metal layer is in contact with the gate dielectric and a top portion of the gate spacer. An epitaxy structure is over the semiconductor fin.

A semiconductor device includes a channel structure, extending along a first lateral direction, that is disposed over a substrate. The semiconductor device includes a gate structure, extending along a second lateral direction perpendicular to the first lateral direction, that straddles the channel structure. The semiconductor device includes an epitaxial structure, coupled to the channel structure, that is disposed next to the gate structure. The semiconductor device includes a first gate spacer and a second gate spacer each comprising a first portion disposed between the gate structure and the epitaxial structure along the first lateral direction. The semiconductor device includes an air gap interposed between the first portion of the first gate spacer and the first portion of the second gate spacer. The air gap exposes a second portion of the first gate spacer that extends in the first lateral direction.

According to one embodiment, a method for manufacturing a semiconductor device includes forming a first metal nitride film on a side surface of a hole extending in a stacking direction in a stacked body. The method includes forming a second metal nitride film on upper and lower surfaces of second layers and a side surface of the first metal nitride film. The method includes forming metal layers in first air gaps inside the second metal nitride film. The method includes removing the second layers and forming second air gaps between the metal layers. The method includes removing the first metal nitride film exposed to the second air gaps and dividing the first metal nitride film in the stacking direction.

A method includes a number of operations. An interlayer dielectric (ILD) layer is formed over a source/drain region on a substrate. A source/drain contact extending through the ILD layer to electrically connect with the source/drain region is formed. An air gap extending through the ILD layer is formed. An implantation energy absorption dielectric layer is formed over the ILD layer. An implantation process is performed on the implantation energy absorption dielectric layer, wherein the implantation process causes the ILD layer expands to seal the air gap. A first implant-free dielectric layer is formed over the implantation energy absorption dielectric layer. A second implant-free dielectric layer is formed over the first implant-free dielectric layer. A source/drain via extending through the second implant-free dielectric layer, the first implant-free dielectric layer, and the implantation energy absorption dielectric layer to the source/drain contact is formed.

Methods of cutting gate structures, and structures formed, are described. In an embodiment, a structure includes first and second gate structures over an active area, and a gate cut-fill structure. The first and second gate structures extend parallel. The active area includes a source/drain region disposed laterally between the first and second gate structures. The gate cut-fill structure has first and second primary portions and an intermediate portion. The first and second primary portions abut the first and second gate structures, respectively. The intermediate portion extends laterally between the first and second primary portions. First and second widths of the first and second primary portions along longitudinal midlines of the first and second gate structures, respectively, are each greater than a third width of the intermediate portion midway between the first and second gate structures and parallel to the longitudinal midline of the first gate structure.