Interconnect structures and method of forming the same are disclosed herein. An exemplary interconnect structure includes a first contact feature in a first dielectric layer, a second dielectric layer over the first dielectric layer, a second contact feature over the first contact feature, a barrier layer between the second dielectric layer and the second contact feature, and a liner between the barrier layer and the second contact feature. An interface between the first contact feature and the second contact feature includes the liner but is free of the barrier layer.

A three-dimensional (3D) metal-insulator-metal capacitor (MIMCAP) includes a plurality of center studs disposed within cavity walls of a plurality of cavities in a top plate. The center studs and the cavity walls are oriented orthogonal to a first metal layer and extend through a first via layer and a second metal layer. Each center stud includes a metal layer stud in the second metal layer stacked on a via layer stud in the first via layer. A dielectric layer is disposed between the center studs and the cavity walls of the plurality of cavities in the top plate. The center studs are coupled to a first electrode, and the top plate is coupled to a second electrode in the interconnect layers. In some examples, the center studs can form vertically oriented cylindrical capacitive elements positioned for high capacitance density.

Embodiments of the disclosure are in the field of advanced integrated circuit structure fabrication and, in particular, 10 nanometer node and smaller integrated circuit structure fabrication and the resulting structures. In an example, an integrated circuit structure includes a fin comprising silicon, the fin having a lower fin portion and an upper fin portion. A gate electrode is over the upper fin portion of the fin, the gate electrode having a first side opposite a second side. A first epitaxial source or drain structure is embedded in the fin at the first side of the gate electrode. A second epitaxial source or drain structure is embedded in the fin at the second side of the gate electrode, the first and second epitaxial source or drain structures comprising silicon and germanium and having a match-stick profile.

A layer of carbon (e.g., graphite or graphene) at a metal interface (e.g., between an MEOL interconnect and a gate contact or a source or drain region contact, between an MEOL contact plug and a BEOL metallization layer, and/or between BEOL conductive structures) is used to reduce contact resistance at the metal interface, which increases electrical performance of an electronic device. Additionally, in some implementations, the layer of carbon may help prevent heat transfer from a second metal to a first metal when the second metal is deposited over the first metal. This results in more symmetric deposition of the second metal, which reduces surface roughness and contact resistance at the metal interface. As an alternative, in some implementations, the layer of carbon is etched before deposition of the second metal in order to reduce contact resistance at the metal interface.

A dielectric layer is located on top of and in contact with a substrate. A conductive line located within the dialectic layer. A barrier layer on top of an in contact with the dielectric layer. The barrier layer is below the conductive line. A liner layer on top of and in contact with the barrier layer and below and in contact with the conductive line. A metal liner on top of and in contact with the conductive line. A capping layer on top of and in contact with the dielectric layer, the barrier layer, the liner layer, and the metal liner.

A method of depositing a metal material on an isolated seed layer uses a barrier layer as a conductive path for plating. The method may include depositing a barrier layer on a substrate wherein the barrier layer provides adhesion for seed layer material and inhibits migration of the seed layer material, forming at least one isolated seed layer area on the barrier layer on the substrate, and depositing the metal material on the at least one isolated seed layer area using an electrochemical deposition process wherein the barrier layer provides a current path to deposit the metal material on the at least one isolated seed layer area.

An interconnection element of an interconnection structure of an integrated circuit is manufactures by a method where a cavity is etched in an insulating layer. A silicon nitride layer is then deposited on walls and a bottom of the cavity. The nitrogen atom concentration in the silicon nitride layer increasing as a distance from an exposed surface of the silicon nitride layer increases. A copper layer is deposited on the silicon nitride layer. The cavity is further filled with copper. A heating process is performed after the deposition of the copper layer, to convert the copper layer and the silicon nitride layer to form a copper silicide layer which has a nitrogen atom concentration gradient corresponding to the gradient of the silicon nitride layer.

The present application discloses a semiconductor device and a method for fabricating the semiconductor device. The semiconductor device includes a substrate, a porous insulating layer positioned above the substrate, a first conductive feature positioned in the porous insulating layer, and covering liners including two top segments and two side segments. The two side segments are positioned on sidewalls of the first conductive feature, and the two top segments are positioned on top surfaces of the porous insulating layer.

A method for CMP includes following operations. A metal stack is received. The metal layer stack includes at least a first metal layer and a second metal layer, and a top surface of the first metal layer and a top surface of the second metal layer are exposed. A protecting layer is formed over the second metal layer. A portion of the first metal layer is etched. The protecting layer protects the second metal layer during the etching of the portion of the first metal layer. A top surface of the etched first metal layer is lower than a top surface of the protecting layer. The protecting layer is removed from the second metal layer.

A method for fabricating a static random access memory (SRAM) includes the steps of: forming a gate structure on a substrate; forming an epitaxial layer adjacent to the gate structure; forming a first interlayer dielectric (ILD) layer around the gate structure; transforming the gate structure into a metal gate; forming a contact hole exposing the epitaxial layer, forming a barrier layer in the contact hole, forming a metal layer on the barrier layer, and then planarizing the metal layer and the barrier layer to form a contact plug. Preferably, a bottom portion of the barrier layer includes a titanium rich portion and a top portion of the barrier layer includes a nitrogen rich portion.