The present disclosure describes a method for forming liner-free or barrier-free conductive structures. The method includes forming a liner-free conductive structure on a cobalt conductive structure disposed on a substrate, depositing a cobalt layer on the liner-free conductive structure and exposing the liner-free conductive structure to a heat treatment. The method further includes removing the cobalt layer from the liner-free conductive structure.

An exemplary device includes a channel layer, a first epitaxial source/drain feature, and a second epitaxial source/drain feature disposed over a substrate. The channel layer is disposed between the first epitaxial source/drain feature and the second epitaxial source/drain feature. A metal gate is disposed between the first epitaxial source/drain feature and the second epitaxial source/drain feature. The metal gate is disposed over and physically contacts at least two sides of the channel layer. A source/drain contact is disposed over the first epitaxial source/drain feature. A doped crystalline semiconductor layer, such as a gallium-doped crystalline germanium layer, is disposed between the first epitaxial source/drain feature and the source/drain contact. The doped crystalline semiconductor layer is disposed over and physically contacts at least two sides of the first epitaxial source/drain feature. In some embodiments, the doped crystalline semiconductor layer has a contact resistivity that is less than about 1×10.sup.−9 Ω-cm.sup.2.

Provided is a semiconductor device which use a two-dimensional semiconductor material as a channel layer. The semiconductor device includes: a gate electrode on a substrate; a gate dielectric on the gate electrode; a channel layer on the gate dielectric; and a source electrode and a drain electrode that may be electrically connected to the channel layer. The gate dielectric has a shape with a height greater than a width, and the channel layer includes a two-dimensional semiconductor material.

A semiconductor structure and a method for forming the same are provided. In one form, the method includes: providing a base, a gate structure being formed on the base, a source/drain doped layer being formed within the base on both sides of the gate structure, and an initial dielectric layer being formed on the base exposed from the gate structure, the initial dielectric layer covering a top of the gate structure, and a source/drain contact plug electrically connected to the source/drain doped layer being formed within the initial dielectric layer on the top of the source/drain doped layer; removing a portion of a thickness of the initial dielectric layer to form a dielectric layer exposing a portion of a side wall of the source/drain contact plug; forming an etch stop layer on at least the side wall of source/drain contact plug exposed from the dielectric layer; etching the dielectric layer on the top of the gate structure using etch stop layers on side walls of adjacent source/drain contact plugs as lateral stop positions, to form a gate contact exposing the top of the gate structure; forming, within the gate contact, a gate contact plug electrically connected to the gate structure. Implementations of the present disclosure facilitate enlargement of a process window for forming a contact over active gate.

Semiconductor device structures are provided. The semiconductor device structure includes a substrate and a first fin structure protruding from the substrate. The semiconductor device structure further includes a gate stack formed across the first fin structure and a first source/drain structure formed over the first fin structure adjacent to the gate stack. The semiconductor device structure further includes a contact structure formed over the first source/drain structure and a dielectric structure formed through the contact structure. In addition, a bottom surface of the contact structure is wider than a top surface of the contact structure.

Described herein are transistor arrangements fabricated by forming a metal gate cut as a trench that is non-selective to the gate sidewalls, in an etch process that can remove both the gate electrode materials and the surrounding dielectrics. Such an etch process may provide improvements in terms of accuracy, cost-efficiency, and device performance, compared to conventional approaches to forming metal gate cuts. In addition, such a process may be used to provide power rails, if the trench of a metal gate cut is to be at least partially filled with an electrically conductive material. Because the electrically conductive material is in the trench and may be in between the fins, as opposed to being provided over the fins, such power rails may be referred to as “recessed.” Providing recessed power rails may provide improvements in terms of reduced metal line resistance and reduced voltage droop.

Gate-all-around integrated circuit structures having source or drain structures with epitaxial nubs, and methods of fabricating gate-all-around integrated circuit structures having source or drain structures with epitaxial nubs, are described. For example, an integrated circuit structure includes a first vertical arrangement of horizontal nanowires and a second vertical arrangement of horizontal nanowires. A first pair of epitaxial source or drain structures includes vertically discrete portions aligned with the first vertical arrangement of horizontal nanowires. A second pair of epitaxial source or drain structures includes vertically discrete portions aligned with the second vertical arrangement of horizontal nanowires. A conductive contact structure is laterally between and in contact with the one of the first pair of epitaxial source or drain structures and the one of the second pair of epitaxial source or drain structures.

A semiconductor device is provided. The semiconductor device includes a fin protruding from a semiconductor substrate and a gate structure formed across the fin. The semiconductor device also includes a gate spacer formed over a sidewall of the gate structure. The gate spacer includes a sidewall spacer and a sealing spacer formed above the sidewall spacer. In addition, an air gap is vertically sandwiched between the sidewall spacer and the sealing spacer. The semiconductor device further includes a hard mask formed over the gate structure and covering a sidewall of the sealing spacer.

There is provided a semiconductor device capable of improving the performance and reliability of a device. The semiconductor device includes comprising a gate structure including a gate electrode and a gate capping pattern on an upper surface of the gate electrode; a source/drain pattern on at least one side of the gate structure; and a source/drain contact on and connected with an upper surface of the source/drain pattern, the source/drain contact extending along a sidewall of the gate electrode, wherein an upper surface of the source/drain contact includes a convex curved surface.

A semiconductor device including first fin-shaped patterns in a first region of a substrate and spaced apart from each other in a first direction, second fin-shaped patterns in a second region of the substrate and spaced apart from each other in a second direction, a first field insulating film on the substrate and covering sidewalls of the first fin-shaped patterns, a second field insulating film on the substrate and covering sidewalls of the second fin-shaped patterns, a first source/drain pattern on the first field insulating film, connected to the first fin-shaped patterns, and including a first silicon-germanium pattern, and a second source/drain pattern on the second field insulating film, connected to the second fin-shaped patterns, and including a second silicon-germanium pattern, the second source/drain pattern and the second field insulating film defining one or more first air gaps therebetween may be provided.