Vias, along with methods for fabricating vias, are disclosed that exhibit reduced capacitance and resistance. An exemplary interconnect structure includes a first source/drain contact and a second source/drain contact disposed in a dielectric layer. The first source/drain contact physically contacts a first source/drain feature and the second source/drain contact physically contacts a second source/drain feature. A first via having a first via layer configuration, a second via having a second via layer configuration, and a third via having a third via layer configuration are disposed in the dielectric layer. The first via and the second via extend into and physically contact the first source/drain contact and the second source/drain contact, respectively. A first thickness of the first via and a second thickness of the second via are the same. The third via physically contacts a gate structure, which is disposed between the first source/drain contact and the second source/drain contact.

Embodiments herein are generally directed to methods of forming high aspect ratio metal contacts and/or interconnect features, e.g., tungsten features, in a semiconductor device. Often, conformal deposition of tungsten in a high aspect ratio opening results in a seam and/or void where the outward growth of tungsten from one or more walls of the opening meet. Thus, the methods set forth herein provide for a desirable bottom up tungsten bulk fill to avoid the formation of seams and/or voids in the resulting interconnect features, and provide an improved contact metal structure and method of forming the same. In some embodiments, an improved overburden layer or overburden layer structure is formed over the field region of the substrate to enable the formation of a contact or interconnect structure that has improved characteristics over conventionally formed contacts or interconnect structures.

Methods for forming a semiconductor structure are described. The method includes cleaning a substrate to form a substrate surface substantially free of oxide, exposing the substrate surface to a first molybdenum precursor, and exposing the substrate surface to a reactant to selectively deposit a first molybdenum film on the substrate surface. The method may be performed in a processing chamber without breaking vacuum. The method may also include forming one or more of a cap layer and a liner and annealing the substrate. The method may also include depositing a second molybdenum film on the substrate surface.

A semiconductor structure including a first dielectric layer comprising a first conductive metal feature embedded in the first dielectric layer; and a second dielectric layer including a second conductive metal feature embedded in the second dielectric layer, the second conductive metal feature is above and directly contacts the first conductive metal feature, and an interface between the second conductive metal feature and the second dielectric layer includes a repeating scallop shape along its entire length.

The present disclosure, in some embodiments, relates to an integrated chip. The integrated chip includes a first interconnect wire arranged within an inter-level dielectric (ILD) layer and a second interconnect wire arranged within the ILD layer. A dielectric material continuously extends over the first interconnect wire and the ILD layer. The dielectric material is further disposed between sidewalls of the first interconnect wire and one or more air-gaps arranged along opposing sides of the first interconnect wire. A via is disposed over the second interconnect wire and extends through the dielectric material. A second ILD layer is disposed on the dielectric material and surrounds the via.

A semiconductor structure is provided. The semiconductor structure includes an epitaxial structure over a semiconductor substrate. The semiconductor structure also includes a conductive feature over the semiconductor substrate. The conductive feature includes a high-k dielectric layer and a metal layer on the high-k dielectric layer, and a top surface of the metal layer is below a top surface of the high-k dielectric layer. The semiconductor structure further includes a metal-semiconductor compound layer formed on the epitaxial structure. In addition, the semiconductor structure includes a first metal contact structure formed on the top surface of the metal layer of the conductive feature. The semiconductor structure further includes a second metal contact structure formed on the metal-semiconductor compound layer.

An integrated circuit structure comprises a first metal layer having first conductive features. A second metal layer has second conductive features. A via layer is in an insulating layer between the first metal layer and the second metal layer. First vias and second vias are formed in the insulating layer. The first vias have a first aspect ratio greater than a second aspect ratio of the second vias. A barrier-less metal partially fills the first vias and fills the second vias. A pure metal fills a remainder of the first vias.

An approach providing a semiconductor wiring structure with a self-aligned top via on a first metal line and under a second metal line. The semiconductor wiring structure includes a plurality of first metal lines in a bottom portion of a first dielectric material. The semiconductor wiring structure includes a top via in a top portion of the first dielectric material, where the top via is over a first metal line of the plurality of first metal lines. The semiconductor wiring structure includes a second dielectric material above each of the plurality of first metal lines except the first metal line of the plurality of first metal lines. Furthermore, the semiconductor wiring structure includes a second metal line above the top via, wherein the second metal line is in a third dielectric material and a hardmask layer that is under the third dielectric material.

A method of gap filling a feature on a substrate decreases the feature-to-feature gap fill height variation by using a tungsten halide soak treatment. In some embodiments, the method may include heating a substrate to a temperature of approximately 350 degrees Celsius to approximately 450 degrees Celsius, exposing the substrate to a tungsten halide gas at a process pressure of approximately 5 Torr to approximately 25 Torr, soaking the substrate for a soak time of approximately 5 seconds to approximately 60 seconds with the tungsten halide gas, and performing a metal preclean process and a gap fill deposition on a plurality of features on the substrate after soaking of the substrate has completed.

An interfacial layer is provided that binds a hydrophilic interlayer dielectric to a hydrophobic gap-filling dielectric. The hydrophobic gap-filling dielectric extends over and fill gaps between devices in an array of devices disposed between two metal interconnect layers over a semiconductor substrate and is the product of a flowable CVD process. The interfacial layer provides a hydrophilic upper surface to which the interlayer dielectric adheres. Optionally, the interfacial layer is also the product of a flowable CVD process. Alternatively, the interfacial layer may be silicon nitride or another dielectric that is hydrophilic. The interfacial layer may have a wafer contact angle (WCA) intermediate between a WCA of the hydrophobic dielectric and a WCA of the interlayer dielectric.