Interconnect structures having dielectric layers with nitrogen-containing crusts and methods of fabrication thereof are disclosed herein. An exemplary method includes forming a first interconnect opening in a first interlayer dielectric (ILD) layer that exposes an underlying conductive feature, such as a source/drain, a gate, a contact, a via, or a conductive line. The method includes nitridizing sidewalls of the first interconnect opening, which are formed by the first ILD layer, before forming a first metal contact in the first interconnect opening. The nitridizing converts a portion of the first ILD layer into a nitrogen-containing crust. The first metal contact can include a metal plug and dielectric spacers between the metal plug and the nitrogen-containing crust of the first ILD layer. The method can include forming a second interconnect opening in a second ILD layer that exposes the first metal contact and forming a second metal contact in the second interconnect opening.

A method includes forming first sacrificial layers and first channel layers alternately stacked over a substrate; forming second channel layers and second sacrificial layers alternately stacked over the first sacrificial layers and the first channel layers, in which the second channel layers are made of a first semiconductive oxide; performing an etching process to remove portions of the first sacrificial layers and the second sacrificial layers; forming a gate structure in contact with the first channel layers and the second channel layers; forming first source/drain contacts on opposite sides of the gate structure and electrically connected to the first channel layers; and forming second source/drain contacts on the opposite sides of the gate structure and electrically connected to the second channel layers.

An integrated circuit structure includes a first interconnect layer including a first dielectric material. The first dielectric material has a first recess therein, the first recess having a first opening. The integrated circuit structure further includes a second interconnect layer above the first interconnect layer. The second interconnect layer includes a second dielectric material that has a second recess therein. The second recess has a second opening. In an example, at least a portion of the first opening of the first recess abuts and overlaps with at least a portion of the second opening of the second recess. In an example, a continuous conformal layer is on walls of the first and second recesses, and a continuous body of conductive material is within the first and second recesses.

A process includes forming, over a dielectric layer, a hardmask stack including a first layer below a second layer below a third layer below a fourth layer. The first and third layers include a different hardmask material from the second and fourth layers. A trench pattern including sidewall spacer structures is formed over the hardmask stack. The fourth layer is etched in a first region. The fourth and third layers are etched in a second region. The fourth and third layers are etched in a third region. The fourth layer is etched in a fourth region. The second and first layers are etched in the second and third regions. The third layer is etched in the first and fourth regions. In the dielectric layer, trenches are formed in the first and fourth regions, and via openings, deeper than the trenches, are formed in the second and third regions.

An upper surface of a plug (PL1) is formed so as to be higher than an upper surface of an interlayer insulating film (PIL) by forming the interlayer insulating film (PIL) on a semiconductor substrate (1S), completing a CMP method for forming the plug (PL1) inside the interlayer insulating film (PIL), and then, making the upper surface of the interlayer insulating film (PIL) to recede. In this manner, reliability of connection between the plug (PL1) and a wiring (W1) in a vertical direction can be ensured. Also, the wiring (W1) can be formed so as not to be embedded inside the interlayer insulating film (PIL), or a formed amount by the embedding can be reduced.

An integrated circuit includes a first and second power rail, a set of active regions, a first set of conductive lines and a first set of vias between the set of active regions and the first set of conductive lines. The first power rail being configured to supply a first supply voltage and being on a first metal layer of a back-side of a substrate. The second power rail being configured to supply a second supply voltage, and being on the first metal layer. The set of active regions being on a first level of a front-side of the substrate opposite from the back-side, overlapping and being electrically coupled to the first and second power rail. The first set of conductive lines being on a second metal layer of the back-side of the substrate, and being overlapped by the set of active regions.

Memory circuitry comprising strings of memory cells comprises laterally-spaced memory blocks individually comprising a vertical stack comprising alternating insulative tiers and conductive tiers. Channel-material strings of memory cells extend through the insulative tiers and the conductive tiers in a memory-array region. The insulative tiers and the conductive tiers of the laterally-spaced memory blocks extend from the memory-array region into a stair-step region. Individual stairs in the stair-step region comprise one of the conductive tiers. Conductive vias are individually directly against conducting material that is in the one conductive tier in one of the individual stairs. Insulator material in the stair-step region is directly above the stairs. An insulative-material lining is circumferentially around and extends elevationally along individual of the conductive vias between the individual conductive vias and the insulator material. Individual of the insulative-material linings and the insulator material comprise an interface there-between. Other embodiments, including methods, are disclosed.

Spacer self-aligned via structures for gate contact or trench contact are described. In an example, an integrated circuit structure includes a plurality of gate structures above a substrate. A plurality of conductive trench contact structures is alternating with the plurality of gate structures. The integrated circuit structure also includes a plurality of dielectric spacers, a corresponding one of the plurality of dielectric spacers between adjacent ones of the plurality of gate structures and the plurality of conductive trench contact structures, wherein the plurality of dielectric spacers protrudes above the plurality of gate structures and above the plurality of conductive trench contact structures. Individual ones of the plurality of dielectric spacers have an upper spacer portion on a lower spacer portion, with an interface between the upper spacer portion and the lower spacer portion.

Semiconductor devices and methods of manufacturing the same are described. The method includes forming distinct and separate bottom dielectric isolation layers underneath the source/drain and underneath the gate of a gate all around device. Selectively remove of the bottom dielectric isolation layer underneath the source/drain results in better backside power rail (BPR) via alignment to the source/drain epi and reduces reliability and gate-shorting problems.

A semiconductor device includes first source/drain (S/D) epitaxy and a second S/D epitaxy and a gate contact. The device also includes a back end of the line (BEOL) layer electrically connected to the first S/D epitaxy and the gate contact on a top side of the device and a wafer that carries the BEOL layer and is on the top side of the device. The device also includes a backside trench epitaxy formed through and contacting portions of the second S/D epitaxy and a backside power distribution network electrically coupled to the backside trench epitaxy and disposed on the bottom of the device.