A structure may include an interconnect-level dielectric layer containing a dielectric material and overlying a substrate, and a metal interconnect structure embedded in the interconnect-level dielectric layer and including a graded metallic alloy layer and a metallic fill material portion. The graded metallic alloy layer includes a graded metallic alloy of a first metallic material and a second metallic material. The atomic concentration of the second metallic material increases with a distance from an interface between the graded metallic alloy and the interconnect-level dielectric layer. The graded metallic alloy layer may be formed by simultaneous or cyclical deposition of the first metallic material and the second metallic material. The first metallic material may provide barrier property, and the second metallic material may provide adhesion property.

A method is presented forming a fully-aligned via (FAV) and airgaps within a semiconductor device. The method includes forming a plurality of copper (Cu) trenches within an insulating layer, forming a plurality of ILD regions over exposed portions of the insulating layer, selectively removing a first section of the ILD regions in an airgap region, and maintaining a second section of the ILD regions in a non-airgap region. The method further includes forming airgaps in the airgap region and forming a via in the non-airgap region contacting a Cu trench of the plurality of Cu trenches.

An etching method is provided for selectively etching a first region of silicon oxide with respect to a second region of silicon nitride by performing plasma processing on a target object including the first region and the second region. In the etch method, first, a plasma of a processing gas including a fluorocarbon gas is generated in a processing chamber where the target object is accommodated. Next, the plasma of the processing gas including the fluorocarbon gas is further generated in the processing chamber where the target object is accommodated. Next, the first region is etched by radicals of fluorocarbon contained in a deposit which is formed on the target object by the generation and the further generation of the plasma of the processing gas containing the fluorocarbon gas. A high frequency powers used for the plasma generation is smaller than a high frequency power used for plasma further generation.

Apparatuses and methods to provide a fully self-aligned via are described. A first metallization layer comprises a set of first conductive lines extending along a first direction on a first insulating layer on a substrate, the set of first conductive lines recessed below a top portion of the first insulating layer. A capping layer is on the first insulating layer, and a second insulating layer is on the capping layer. A second metallization layer comprises a set of second conductive lines on the second insulating layer and on a third insulating layer above the first metallization layer. The set of second conductive lines extend along a second direction that crosses the first direction at an angle. At least one via is between the first metallization layer and the second metallization layer. The via is self-aligned along the second direction to one of the first conductive lines. The tapering angle of the via opening may be in a range of from about 60° to about 120°.

Test pad structures and methods of forming a test pad are described herein. A method for forming a test pad includes forming a device element over a substrate, depositing a dielectric layer over the device element and the substrate, and etching openings in the dielectric layer to a first depth. Once the openings have been formed, a conductive material is deposited in the openings and followed by a chemical mechanical planarization to form a first grid feature and a panel region of the test pad, the first grid feature extending lengthwise from the panel region to a perimeter of the test pad. Once formed, a probe may be used to contact the panel region of the test pad during a wafer acceptance test (WAT) and/or a process control monitoring (PCM) test of the device element.

A method includes depositing a mask layer over a dielectric layer, patterning the mask layer to form a trench, applying a patterned photo resist having a portion over the mask layer, and etching the dielectric layer using the patterned photo resist as an etching mask to form a via opening, which is in a top portion of the dielectric layer. The method further includes removing the patterned photo resist, and etching the dielectric layer to form a trench and a via opening underlying and connected to the trench. The dielectric layer is etched using the mask layer as an additional etching mask. A polymer formed in at least one of the trench and the via opening is removed using nitrogen and argon as a process gas. The trench and the via opening are filled to form a metal line and a via, respectively.

A method for manufacturing an interconnection structure includes forming a second dielectric layer on a wafer. The wafer includes a first dielectric layer and a conductive element embedded in the first dielectric layer. An opening is formed in the second dielectric layer to expose the conductive element. A dielectric spacer layer is selectively formed to be in contact with surfaces defining the opening of the second dielectric layer. The dielectric spacer layer exposes the conductive element. A bottom via is formed in the opening and in contact with the dielectric spacer layer and the conductive element. A portion of the dielectric spacer layer is removed to form a dielectric spacer in contact with the bottom via. A top via is formed in the opening and over the bottom via and the dielectric spacer.

The present disclosure relates to semiconductor structures and, more particularly, to skip via structures and methods of manufacture. The structure includes: a first wiring layer with one or more wiring structures; an upper wiring layer with one or more wiring structures, located above the first wiring layer; a blocking material which contacts at least one of the wiring structures of the upper wiring layer; a skip via with metallization, the skip via passes through the upper wiring layer and makes contact with the one or more wiring structures of the first wiring layer; and a conductive material in the skip via above the metallization and in a via interconnect above the blocking material.

A semiconductor structure including a substrate, a first dielectric layer, a first conductive feature, an etch stop layer, a second dielectric layer and a second conductive feature is provided. The first dielectric layer is disposed over the substrate. The first conductive feature is disposed in the first dielectric layer. The etch stop layer is disposed over the first dielectric layer and the first conductive feature, wherein the etch stop layer comprises a metal-containing layer and a silicon-containing layer, the metal-containing layer is located between the first dielectric layer and the silicon-containing layer, the metal-containing layer comprises a nitride-containing region and an oxide-containing region, and the nitride-containing region contacts the first conductive feature. The second dielectric layer is disposed over the etch stop layer. The second conductive feature penetrates the second dielectric layer and electrically connects with the first conductive feature.

An etching method including: (a) providing a workpiece including a first region made of a first material and a second region made of a second material defining a recess, the first region filling the recess of the second region while covering the second region; (b) generating plasma of a first fluorocarbon gas to etch the first region until before exposing the second region; (c) generating plasma of a second fluorocarbon gas to form fluorocarbon deposits on the first region; (d) generating plasma of an inert gas to etch the first region by fluorocarbon radicals contained in the fluorocarbon deposits; and (e) repeating step (c) and step (d) one or more times until after exposing the second region. An etching rate of the first material of the first region is higher than that of the second material of the second region with respect to the second fluorocarbon gas.