Techniques for low- or zero-misaligned vias are disclosed. In one embodiment, a high-photosensitivity, medium-photosensitivity, and low-photosensitivity layer are applied to a substrate and exposed at the same time with use of a multi-tone mask. After being developed, one layer forms a mold for a first via, one layer forms a mold for a conductive trace and a second via, and one layer forms an overhang over the position for the second via. The molds formed by the photosensitive layers are filled with copper and then etched. The overhang prevents the top of the copper infill below the overhang region from being etched. As such, the region under the overhang forms a pillar or column after etching, which can be used as a via. Other embodiments are disclosed.

A semiconductor device includes a substrate including a cell region and a peripheral circuit region; a conductive structure on the cell region and the peripheral circuit region, the conductive structure extending in a first direction parallel to an upper surface of the substrate; a gate structure on the peripheral circuit region, the gate structure spaced apart from the conductive structure in the first direction; a spacer contacting a sidewall of the gate structure; and a first capping pattern contacting a sidewall of an end portion in the first direction of the conductive structure and a sidewall of the spacer, wherein the spacer and the first capping pattern include different insulating materials.

An interconnection structure includes a first dielectric layer, a first conductive feature, a first liner layer, a second conductive feature, a second liner layer, and an air gap. The first conductive feature is disposed in the first dielectric layer. The first liner layer is disposed between the first conductive feature and the first dielectric layer. The second conductive feature penetrates the first dielectric layer. The second liner layer is disposed between the second conductive feature and the first dielectric layer. The air gap is disposed in the first dielectric layer between the first liner layer and the second liner layer. The first liner layer and the second liner layer include metal oxide, metal nitride, or silicon oxide doped carbide.

A semiconductor structure includes a gate structure over a substrate. The structure also includes a source/drain epitaxial structure formed on opposite sides of the gate structure. The structure also includes a contact structure formed over the gate structure. The structure also includes a metal layer formed over the contact structure. The structure also includes a cap layer formed over the metal layer. The structure also includes a first etch stop layer including a metal compound formed over the cap layer. The structure also includes a second etch stop layer including nitrogen formed over the first etch stop layer. The structure also includes a via structure that passes through the first etch stop layer and the second etch stop layer. The bottom surface of the cap layer is level with the bottom surface of the first etch stop layer

In a semiconductor process, a seamless tungsten plug is formed in an inter-layer dielectric by forming the inter-layer dielectric from multiple oxide layers having different wet etch rates, from lowest wet-etch rate for the lowest layer to highest wet-etch rate for the highest layer, forming a hole or trench in the inter-layer dielectric using a dry etch process, reconfiguring the hole or trench to have sloped side walls by performing a wet etch step, and filling the hole or trench with tungsten and etching back the tungsten to form a seamless tungsten plug.

A semiconductor device structure and method for forming the same are provided. The semiconductor device structure includes a first metal layer formed over a substrate and a dielectric layer formed over the first metal layer. The semiconductor device structure further includes an adhesion layer formed in the dielectric layer and over the first metal layer and a second metal layer formed in the dielectric layer. The second metal layer is electrically connected to the first metal layer, and a portion of the adhesion layer is formed between the second metal layer and the dielectric layer. The adhesion layer includes a first portion lining with a top portion of the second metal layer, and the first portion has an extending portion along a vertical direction.

A semiconductor structure includes a metal gate structure disposed over a semiconductor substrate, an interlayer dielectric (ILD) layer disposed over the metal gate structure, and a gate contact disposed in the ILD layer and over the metal gate structure, where a bottom surface of the gate contact is defined by a barrier layer disposed over the metal gate structure, where sidewall surfaces of the gate contact are defined by and directly in contact with the ILD layer, and where the barrier layer is free of nitrogen.

A method and semiconductor device including a substrate having one or more semiconductor devices. In some embodiments, the device further includes a first passivation layer disposed over the one or more semiconductor devices. The device may further include a metal-insulator-metal (MIM) capacitor structure formed over the first passivation layer. In addition, the device may further include a second passivation layer disposed over the MIM capacitor structure. In various examples, a stress-reduction feature is embedded within the second passivation layer. In some embodiments, the stress-reduction feature includes a first nitrogen-containing layer, an oxygen-containing layer disposed over the first nitrogen-containing layer, and a second nitrogen-containing layer disposed over the oxygen containing layer.

Interconnect structures exhibiting reduced accumulation of copper vacancies along interfaces between contact etch stop layers (CESLs) and interconnects, along with methods for fabrication, are disclosed herein. A method includes forming a copper interconnect in a dielectric layer and depositing a metal nitride CESL over the copper interconnect and the dielectric layer. An interface between the metal nitride CESL and the copper interconnect has a first surface nitrogen concentration, a first nitrogen concentration and/or a first number of nitrogen-nitrogen bonds. A nitrogen plasma treatment is performed to modify the interface between the metal nitride CESL and the copper interconnect. The nitrogen plasma treatment increases the first surface nitrogen concentration to a second surface nitrogen concentration, the first nitrogen concentration to a second nitrogen concentration, and/or the first number of nitrogen-nitrogen bonds to a second number of nitrogen-nitrogen bonds, each of which minimizes accumulation of copper vacancies at the interface.

A semiconductor structure and a method for forming the same are disclosed. The method includes the steps of forming a first dielectric layer on a substrate, forming a plurality of first interconnecting structures in the first dielectric layer, forming at least a trench in the first dielectric layer and between the first interconnecting structures, performing a sputtering deposition process to form a second dielectric layer on the first dielectric layer, wherein the second dielectric layer at least partially seals an air gap in the trench, and forming a third dielectric layer on the second dielectric layer.