Methods of and systems for reforming films comprising silicon nitride are disclosed. Exemplary methods include providing a substrate within a reaction chamber, forming activated species by irradiating a reforming gas with microwave radiation, and exposing substrate to the activated species. A pressure within the reaction chamber during the step of forming activated species can be less than 50. Pa.

The present disclosure provides an interconnect structure and a method for forming an interconnect structure. The method for forming an interconnect structure includes forming a first interlayer dielectric (ILD) layer over a substrate, forming a contact in the first ILD layer, forming a second ILD layer over the first ILD layer, forming a first opening in the second ILD layer and obtaining an exposed side surface of the second ILD layer over the contact, forming a densified dielectric layer at the exposed side surface of the second ILD layer, including oxidizing the exposed side surface of the second ILD layer by irradiating a microwave on the second ILD layer, and forming a via in contact with the densified dielectric 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 method for forming an interconnect structure is described. In some embodiments, the method includes forming a conductive layer, removing portions of the conductive layer to form a via portion extending upward from a bottom portion, forming a sacrificial layer over the via portion and the bottom portion, recessing the sacrificial layer to a level substantially the same or below a level of a top surface of the bottom portion, forming a first dielectric material over the via portion, the bottom portion, and the sacrificial layer, and removing the sacrificial layer to form an air gap adjacent the bottom portion.

A method for making a semiconductor structure, including: forming a conductive layer; forming a patterned mask layer on the conductive layer; patterning the conductive layer to form a recess and a conductive feature; forming a first dielectric layer over the patterned mask layer and filling the recess with the first dielectric layer; patterning the first dielectric layer to form an opening; selectively forming a blocking layer in the opening; forming an etch stop layer to cover the first dielectric layer and exposing the blocking layer; forming on the etch stop layer a second dielectric layer; forming a second dielectric layer on the etch stop layer; patterning the second dielectric layer to form a through hole and exposing the conductive feature; and filling the through hole with an electrically conductive material to form an interconnect electrically connected to the conductive feature.

A semiconductor structure includes a substrate with a conductive structure thereon, a first dielectric layer, a conductive feature and a second dielectric layer. The substrate includes a conductive feature. The conductive feature is formed in the first dielectric layer, is electrically connected to the conductive feature. The second dielectric layer is formed on the first dielectric layer and is disposed adjacent to the conductive feature. The first dielectric layer and the second dielectric layer are made of different materials.

A semiconductor structure includes a first dielectric layer, a first conductive feature, a second conductive feature, a first etch stop layer, and a conductive via. The first conductive feature and the second conductive feature are embedded in the first dielectric layer. The first etch stop layer is disposed over the dielectric layer. The conductive via is surrounded by the first etch stop layer and electrically connected to the first conductive feature, in which the conductive via is in contact with a top surface of the first etch stop layer.

A semiconductor device includes: a first conductive structure having sidewalls and a bottom surface, the first conductive structure extending through one or more isolation layers formed on a substrate; and an insulation layer disposed between at least one of the sidewalls of the first conductive structure and respective sidewalls of the one or more isolation layers, wherein the first conductive structure is electrically coupled to a second conductive structure through at least the bottom surface.

A method comprises forming a gate structure over a semiconductor substrate; forming an etch stop layer over the gate structure and an ILD layer over the etch stop layer; performing a first etching process to form a gate contact opening extending through the ILD layer into the etch stop layer, resulting in a sidewall of the etch stop layer being exposed in the gate contact opening; oxidizing the exposed sidewall of the etch stop layer; after oxidizing the exposed sidewall of the etch stop layer, performing a second etching process to deepen the gate contact opening; and forming a gate contact in the deepened gate contact opening.

A semiconductor structure and a method for forming a semiconductor structure are provided. In some embodiments, a method is provided. The method includes following operations. A sacrificial gate structure is formed over a fin structure. The sacrificial gate structure includes a sacrificial gate layer and a sacrificial dielectric layer. The sacrificial gate layer is removed to form a gate trench exposing the sacrificial dielectric layer. A doped region is formed in the fi structure covered by the sacrificial dielectric layer. The sacrificial dielectric layer, a portion of the doped region and a portion of the fin structure are removed from the gate trench. An interfacial layer is formed over the fin structure in the gate trench.