Formation of oxidation-resistant seed layer for interconnect applications
View Patent ↗An interconnect structure of the single or dual damascene type and a method of forming the same, which substantially reduces the surface oxidation problem of plating a conductive material onto a noble metal seed layer are provided. In accordance with the present invention, a hydrogen plasma treatment is used to treat a noble metal seed layer such that the treated noble metal seed layer is highly resistant to surface oxidation. The inventive oxidation-resistant noble metal seed layer has a low C content and/or a low nitrogen content.
1. A method of forming an interconnect structure comprising:
forming at least one opening in a dielectric material;
forming a diffusion barrier on exposed wall portions of said dielectric material within said at least one opening;
forming an oxidation-resistant noble metal seed layer on said diffusion barrier, said oxidation-resistant noble metal seed layer comprises a noble metal seed layer having an upper surface region that is resistant to oxidation; and
forming an interconnect conductive material within said at least one opening atop said oxidation-resistant noble metal seed layer.
2. The method of forming an interconnect structure according to claim 1 wherein said forming said at least one opening comprises lithography and etching one of a line opening, a via opening and a line opening or a combination of said openings.
3. The method of forming an interconnect structure according to claim 1 wherein said forming said oxidation-resistant noble metal seed layer comprises depositing a layer of a noble metal or noble metal alloy and subjecting said layer to a H 2 plasma treatment.
4. The method of forming an interconnect structure according to claim 3 wherein said H 2 plasma treatment comprises from about 0 to about 85% N 2 .
5. The method of forming an interconnect structure according to claim 1 further comprising removing a portion of said diffusion barrier within a bottom portion of said at least one opening which is in contact with at underlying conductive feature, said removing of said portion of said diffusion barrier is performed prior to forming said oxidation-resistant noble metal seed layer.
6. The method of forming an interconnect structure according to claim 1 further comprising removing a portion of a conductive feature located beneath and in contact with said at least one opening to provide a recessed area within said conductive feature prior to forming said diffusion barrier and removing said diffusion barrier in said recessed area prior to forming said oxidation-resistant noble metal seed layer within said at least one opening.
7. A method of comprising:
forming a noble metal seed layer on a surface of a substrate;
treating said noble metal seed layer in a hydrogen plasma to provide an oxidation-resistant noble metal seed layer, said oxidation-resistant noble metal seed layer comprises a noble metal seed layer having an upper surface region that is resistant to oxidation; and
forming a conductive material on said noble metal seed layer.
8. A method of forming an interconnect structure comprising:
forming at least one opening in a dielectric material;
forming a diffusion barrier on exposed wall portions of said dielectric material within said at least one opening;
forming an oxidation-resistant noble metal seed layer on said diffusion barrier, said forming said oxidation-resistant noble metal seed layer comprises depositing a layer of a noble metal or noble metal alloy and subjecting said layer to a H 2 plasma treatment wherein said H 2 plasma treatment comprises from about 0 to about 85% N 2 ; and
forming an interconnect conductive material within said at least one opening atop said oxidation-resistant noble metal seed layer.
9. The method of forming an interconnect structure according to claim 1 wherein said upper surface region has a carbon content of about 2 atomic percent or less.
10. The method of forming an interconnect structure according to claim 1 wherein said upper surface region has a nitrogen content of about 3 atomic percent or less.
11. The method of forming an interconnect structure according to claim 1 wherein said oxidation-resistant noble metal seed layer comprises a metal or metal alloy from Group VIIIA of the Periodic Table of Elements.
12. The method of forming an interconnect structure according to claim 11 wherein said oxidation-resistant noble metal seed layer comprises Ru, Ir, or Rh.
13. The method of claim 7 wherein said upper surface region has a carbon content of about 2 atomic percent or less.
14. The method of claim 7 wherein said upper surface region has a nitrogen content of about 3 atomic percent or less.
15. The method of claim 7 wherein said oxidation-resistant noble metal seed layer comprises a metal or metal alloy from Group VIIIA of the Periodic Table of Elements.
16. The method of claim 15 wherein said oxidation-resistant noble metal seed layer comprises Ru, Ir, or Rh.