Middle of line cobalt interconnection
A method of fabricating features of a semiconductor device includes forming a contact over a substrate, the contact including a cobalt core and a liner layer arranged on sidewalls, wherein the contact includes a portion that is laterally surrounded by an interlevel dielectric (ILD); depositing another layer of ILD on the contact; etching a first opening in the ILD to expose a surface of the contact; removing the liner layer of the contact to expose a portion of the cobalt core; etching the ILD that laterally surrounds the contact to form a second opening beneath the first opening, the second opening having a width that is less than the first opening; depositing a liner on sidewalls of the first opening, the second opening, and directly on the cobalt core; and depositing a metal on the liner layer to form an interconnect structure.
1. A method of fabricating features of a semiconductor device, the method comprising:
forming a contact over a substrate, the contact comprising a cobalt core and a liner layer arranged on sidewalls, wherein the contact includes a portion that is laterally surrounded by an interlevel dielectric (ILD);
depositing an another layer of ILD on the contact;
etching a first opening in the another layer of ILD to expose a surface of the contact;
removing the liner layer of the contact to expose a portion of the cobalt core;
etching the ILD that laterally surrounds the contact to form a second opening beneath the first opening, the second opening having a width that is less than the first opening;
depositing a liner on sidewalls of the first opening, the second opening, and directly on the cobalt core; and
depositing a metal on the liner layer to form an interconnect structure.
2. The method of claim 1 , wherein the contact comprises an oxidation layer on a surface of the cobalt core.
3. The method of claim 2 further comprising removing the oxidation layer after etching the first opening.
4. The method of claim 1 , wherein the contact comprises a source/drain contact.
5. The method of claim 1 , wherein an oxidation layer on the cobalt core is exposed after etching the first opening in the ILD.
6. The method of claim 1 , wherein the contact comprises a source/drain contact, and the source/drain contact further comprises a silicide that is arranged between a source/drain region and the liner.
7. The method of claim 6 , wherein the silicide comprises titanium silicide.
8. The method of claim 1 , wherein the contact comprises a gate contact.
9. A semiconductor device, comprising:
a contact comprising a cobalt core;
an interlevel dielectric (ILD) disposed on the contact;
an opening extending through the ILD and around the contact, the opening having a first portion and a second portion, the first portion arranged over the second portion and having a width that is greater than the first portion, and a portion of the cobalt core extending into the first portion of the opening; and
a metal disposed in the opening and around a portion of the cobalt core to form an interconnect structure over the contact.
10. The semiconductor device of claim 9 , wherein the contact comprises a source/drain contact arranged on a source/drain region.
11. The semiconductor device of claim 9 , wherein the contact comprises a gate contact arranged on a gate.
12. The semiconductor device of claim 9 , wherein the metal is disposed directly on the cobalt core.
13. The semiconductor device of claim 9 further comprising a liner arranged between the metal and the cobalt core of the contact.
14. The semiconductor device of claim 13 , wherein the contact further comprises a liner arranged on sidewalls of the cobalt core.