A semiconductor device includes a substrate, an active pattern disposed on the substrate and that extends in a first horizontal direction, a field insulating layer disposed on the substrate and that surrounds a sidewall of the active pattern, a gate electrode disposed on the field insulating layer and that extends in a second horizontal direction, a source/drain region disposed on a side of the gate electrode, a first interlayer insulating layer disposed on the field insulating layer and that surrounds a portion of a sidewall of the source/drain region, a second interlayer insulating layer disposed on the first interlayer insulating layer and that surrounds a sidewall of the gate electrode, and a source/drain contact that penetrates through the second interlayer insulating layer and is electrically connected to the source/drain region. The source/drain contact includes a skirt that protrudes from a lower sidewall toward the second interlayer insulating.

A method of fabricating an air gap includes receiving a first thickness information of an inter-metal dielectric layer formed on a substrate and receiving a second thickness information of an inter-layer dielectric layer formed on the substrate. Then, a first etching is performed, wherein the first etching includes etch the inter-metal dielectric layer based on a first etching control value corresponding to the first thickness information. After the first etching, a second etching is performed to etch the inter-layer dielectric layer based on a second etching control value corresponding to the second thickness information.

Semiconductor devices including backside vias with enlarged backside portions and methods of forming the same are disclosed. In an embodiment, a device includes a first transistor structure in a first device layer; a front-side interconnect structure on a front-side of the first device layer; a first dielectric layer on a backside of the first device layer; a first contact extending through the first dielectric layer to a source/drain region of the first transistor structure; and a backside interconnect structure on a backside of the first dielectric layer and the first contact, the first contact including a first portion having first tapered sidewalls and a second portion having second tapered sidewalls, widths of the first tapered sidewalls narrowing in a direction towards the backside interconnect structure, and widths of the second tapered sidewalls widening in a direction towards the backside interconnect structure.

An integrated circuit (IC) with through-circuit vias (TCVs) and methods of forming the same are disclosed. The IC includes a semiconductor device, first and second interconnect structures disposed on first and second surfaces of the semiconductor device, respectively, first and second inter-layer dielectric (ILD) layers disposed on front and back surfaces of the substrate, respectively, and a TCV disposed within the first and second interconnect structures, the first and second ILD layers, and the substrate. The TCV is spaced apart from the semiconductor device by a portion of the substrate and portions of the first and second ILD layers. A first end of the TCV, disposed over the front surface of the substrate, is connected to a conductive line of the first interconnect structure and a second end of the TCV, disposed over the back surface of the substrate, is connected to a conductive line of the second interconnect structure.

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.

The present disclosure provides a semiconductor device structure that includes: a fin active region extruded above a semiconductor substrate; a gate stack disposed on the fin active region, wherein the gate stack includes a gate dielectric layer and a gate electrode; source/drain (S/D) features formed on the fin active region and interposed by the gate stack; and a conductive feature electrically connected to the gate electrode or the S/D features. The conductive feature includes a bottom metal feature of a first metal; a top metal feature of a second metal over the bottom metal feature, wherein the second metal is different from the first metal in composition; a barrier layer surrounding both the top metal feature and the bottom metal feature; and a liner surrounding both the top metal feature and separating the top metal feature from the bottom metal feature and the barrier layer.

Metal nitride diffusion barriers may be included between cobalt-based structures and ruthenium-based structures to reduce, minimize, and/or prevent intermixing of cobalt into ruthenium. A metal nitride diffusion barrier layer may include a cobalt nitride (CoN.sub.x), a ruthenium nitride (RuN.sub.x), or another metal nitride that has a bond dissociation energy greater than the bond dissociation energy of cobalt to cobalt (Co—Co), and may therefore function as a strong barrier to cobalt migration and diffusion into ruthenium. Moreover, cobalt nitride and ruthenium nitride have lower resistivity relative to other materials such as titanium nitride (TiN), tungsten nitride (WN), and tantalum nitride (TaN). In this way, the metal nitride diffusion barriers are capable of minimizing cobalt diffusion and intermixing into ruthenium-based interconnect structures while maintaining a low contact resistance for the interconnect structures. This may increase semiconductor device performance, may increase semiconductor device yield, and may enable further reductions in interconnect structure size.

Structures and methods of forming semiconductor devices are presented in which a void-free core-shell hard mask is formed over a gate electrode. The void-free core-shell hard mask may be formed in some embodiments by forming a first liner layer over the gate electrode, forming a void-free material over the first liner layer, recessing the void-free material, and forming a second liner over the recessed void-free material.

An integrated circuit device includes a semiconductor substrate having a first surface and a second surface opposite to the first surface, a first insulating layer on the first surface of the semiconductor substrate, an electrode landing pad positioned on the first surface of the semiconductor substrate and having a sidewall surrounded by the first insulating layer, a top surface apart from the first surface of the semiconductor substrate, and a bottom surface opposite to the top surface, and a through-electrode configured to penetrate through the semiconductor substrate and contact the top surface of the electrode landing pad, wherein a horizontal width of the top surface of the electrode landing pad is less than a horizontal width of the bottom surface of the electrode landing pad and greater than a horizontal width of a bottom surface of the through-electrode in contact with the top surface of the electrode landing pad.

A method of making a semiconductor device includes forming a conductive element over a substrate, depositing a layer of dielectric material over the conductive element, etching the layer of dielectric material to define an opening, where a dimension of the opening adjacent the conductive element has a first width measured in a direction parallel to a top surface of the substrate, reducing the first width by depositing a dielectric liner in the opening, etching the dielectric liner to expose a portion of the conductive element, where a dimension of the conductive element exposed has a second width less than the first width, depositing a conductive material in the opening, where the dielectric layer is between the conductive material and the layer of dielectric material, and the conductive material is electrically connected to the conductive element.