Additive core subtractive liner for metal cut etch processes
An additive core subtractive liner method is described for forming electrically conductive contacts. The method can include forming a first trench in an first dielectric layer to expose a first portion of a metal liner, and filling said first trench with a second dielectric layer. A metal cut trench is formed in the second dielectric layer. A portion of the metal liner exposed by the metal cut trench is removed with a subtractive method. The method continues with filling the metal cut trench with a dielectric fill, and replacing the remaining portions of the second dielectric layer with an additive core conductor to provide contacts to remaining portions of the metal liner.
1. An electrical conductive structure to an electrical device comprising:
a first portion of a metal liner present on a first device feature that is separated from a second portion of the metal liner that is present on a second device feature, the first device feature being a first merged epitaxial material between two first fin structures and the second device feature being a second merged epitaxial material between two second fin structures, wherein the first merged epitaxial material and the first portion of the metal liner encapsulate an entire height of the first fin structures and the second merged epitaxial material and the second portion of the metal liner encapsulate an entire height of the second fin structures;
a dielectric fill material entirely filling a space between the first portion of the metal liner and the second portion of the metal liner, the dielectric fill having a greater width at its upper surface than at a lower surface of the dielectric fill, wherein a liner layer is not present underlying the dielectric fill between the first and second portions of the metal liner, the dielectric fill providing a trench isolation region separating the first device feature from the second device feature;
electrical contacts provided by an additive core that are present on opposing sides of and in direct contact with the dielectric fill material, wherein the electrical contacts are in electrical communication with the first and second portion of the metal liner that is present on the source and drain regions, the electrical contacts having a lesser width at its upper surface than at a lower surface of the electrical contact and a planar sidewall along a single plane that intersects with a base of the electrical contact at an acute angle; and
a metal line in the trench isolation region.
2. The electrical conductive structure of claim 1 , wherein each of the first and second portions of the metal liner are in contact with source/drain regions of a semiconductor device.
3. The electrical conductive structure of claim 1 , wherein each of the first and second portions of the metal liner are within a gate structure produced using replacement metal gate processing.
4. The electrical conductive structure of claim 1 , wherein each of the first and second portions of the metal liner are a component of an interconnect formed during back end of the line (BEOL) processing.
5. The electrical conductive structure of claim 1 , wherein a composition of the metal liner is selected from the group consisting of tungsten, cobalt, and titanium.
6. The electrical conductive structure of claim 1 , wherein a composition of the metal liner includes titanium nitride.