Process integration approach for selective metal via fill
Methods and apparatus for an interconnect formed on a substrate and a method of forming the interconnect thereon. In embodiments, the methods include etching through a hard mask disposed atop a low-k dielectric layer to form a via through the low-k dielectric layer and expose a conductive surface; contacting the conductive surface with dilute hydrofluoric acid to remove contaminants therefrom; removing the hard mask disposed atop the low-k dielectric layer; and applying a remote hydrogen plasma to the conductive surface to form an exposed portion of the conductive surface.
1. A method of forming an interconnect, comprising:
etching through a hard mask disposed atop a low-k dielectric layer to form a via through the low-k dielectric layer and expose a conductive surface;
contacting the conductive surface with dilute hydrofluoric acid to remove contaminants therefrom;
subsequently, removing the hard mask disposed atop the low-k dielectric layer;
subsequent to removing the hard mask, applying a remote hydrogen plasma to the exposed portion of the conductive surface to clean the exposed portion of the conductive surface;
depositing a first metal of a first type in the via;
forming a trench in communication with the via;
depositing a barrier layer within the trench and atop the exposed portion of the conductive surface;
depositing a liner layer atop the barrier layer; and
filling the trench with a second metal different than the first metal of a first type.
2. The method of claim 1 , wherein contacting the conductive surface with dilute hydrofluoric acid to remove contaminants therefrom is performed before removing the hard mask disposed atop the low-k dielectric layer.
3. The method of claim 1 , wherein removing the hard mask disposed atop the low-k dielectric layer is performed before applying a remote hydrogen plasma to the conductive surface to form an exposed portion of the conductive surface.
4. The method of claim 1 , wherein the dilute hydrofluoric acid is a 100 to 1000:1 dHF solution.
5. The method of claim 1 , wherein the first metal of a first type is one of ruthenium, tungsten, cobalt, aluminum, or combinations thereof.
6. The method of claim 1 , further comprising adding a capping layer atop the second metal.
7. A method of forming an interconnect, comprising:
forming a via and a trench in a film stack comprising a hard mask and a dielectric layer disposed on a substrate to expose a conductive surface;
contacting the conductive surface with dilute hydrofluoric acid;
removing the hard mask;
applying a remote plasma to the exposed conductive surface to clean the exposed portion of the conductive surface;
depositing a first metal of a first type in the via;
depositing a barrier layer upon the first metal and exposed surfaces of the trench;
depositing a liner layer upon the barrier layer; and
filling the trench with a second metal different than the first metal.
8. The method of claim 7 , wherein contacting the conductive surface with dilute hydrofluoric acid occurs prior to removing the hard mask.
9. The method of claim 7 , wherein contacting the conductive surface with dilute hydrofluoric acid occurs prior to removing the hard mask, and wherein removing the hard mask occurs prior to applying a remote plasma to the conductive surface to form an exposed portion of the conductive surface.
10. The method of claim 7 , wherein the first metal of a first type is one of ruthenium, tungsten, cobalt, aluminum, or combinations thereof.
11. The method of claim 7 , wherein the barrier layer comprises TiN or TaN.
12. The method of claim 7 , wherein the liner layer corn cobalt.
13. The method of claim 7 , wherein the second metal is copper.
14. The method of claim 7 , wherein a capping layer is disposed atop the second metal.
15. A non-transitory computer readable medium having instructions stored thereon that, when executed, cause a method a method of forming an interconnect, comprising:
etching through a hard mask disposed atop a low-k dielectric layer to form a via through the low-k dielectric layer and expose a conductive surface;
contacting the conductive surface with dilute hydrofluoric acid to remove contaminants therefrom;
subsequently, removing the hard mask disposed atop the o k dielectric layer;
subsequent to removing the hard mask, applying a remote hydrogen plasma to the exposed portion of the conductive surface to clean the exposed portion of the conductive surface;
depositing a first metal of a first type in the via;
forming a trench in communication with the via;
depositing a barrier layer within the trench and atop the exposed portion of the conductive surface;
depositing a liner layer atop the barrier layer; and
filling the trench with a second metal different than the first metal of a first type.