Nanoscale interconnect structure

Patent metadata

Field	Value
Publication number	US-9613900-B2
Application number	US-201615012492-A
Country	US
Kind code	B2
Filing date	Feb 1, 2016
Priority date	Feb 10, 2014
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

An interconnect structure includes a first dielectric material having an undercut region located at an upper surface thereof. A first conductive structure is located above a first area of the undercut region. The first conductive structure comprises a first conductive metal portion having a diffusion barrier portion located on one sidewall surface of the first conductive metal portion and having a metal liner located on another sidewall surface and a bottom surface of the first conductive metal portion. A second conductive structure is located above a second area of the undercut region. The second conductive structure comprises a second conductive material portion having a diffusion barrier portion located on one sidewall surface of the second conductive material portion and having a metal liner located on another sidewall surface and a bottom surface of the second conductive metal portion. A gap is located between the first and second conductive structures.

First claim

What is claimed is:

1. An interconnect structure comprising:
a first dielectric material having an undercut region located at an upper surface thereof;
a first conductive structure located above a first area of said undercut region, wherein said first conductive structure comprises a first conductive metal portion having a diffusion barrier portion located on one sidewall surface of said first conductive metal portion and having a metal liner located on another sidewall surface and an entire bottom surface of said first conductive metal portion, wherein said first area of said undercut region extends entirely beneath said bottom surface of said first conductive structure and wherein said metal liner located on said entire bottom surface of said first conductive metal portion extends into said first area of said undercut region and is located beneath a topmost surface of said first dielectric material;
a second conductive structure located above a second area of said undercut region, wherein said second conductive structure comprises a second conductive material portion having a diffusion barrier portion located on one sidewall surface of said second conductive material portion and having a metal liner located on another sidewall surface and an entire bottom surface of said second conductive metal portion, wherein said second area of said undercut region extends entirely beneath said bottom surface of said second conductive structure and wherein said metal liner located on said entire bottom surface of said second conductive metal portion extends into said second area of said undercut region and is located beneath said topmost surface of said first dielectric material; and
a gap located between said first conductive structure and said second conductive structure.

2. The interconnect structure of claim 1 , wherein said gap and said undercut region contain air, and wherein a cap layer is located atop an upper surface of said first conductive structure and said second conductive structure.

3. The interconnect structure of claim 1 , wherein said gap and said undercut region contain another dielectric material.

4. The interconnect structure of claim 1 , further comprising a second dielectric material portion located adjacent each sidewall surface of said first and second conductive structures containing said diffusion barrier portion, wherein each second dielectric material is present on a portion of said upper surface of said first dielectric material not including said undercut region.

5. The interconnect structure of claim 4 , wherein said gap and said undercut region contain a third dielectric material.

6. The interconnect structure of claim 5 , wherein an upper surface of said third dielectric material is coplanar with an upper surface of each second dielectric material portion, an upper surface of each diffusion barrier portion and an upper surface of said first and second conductive metal portions.

7. The interconnect structure of claim 1 , wherein said diffusion barrier portion and said metal liner comprise a different material.

8. The interconnect structure of claim 1 , wherein said diffusion barrier portion and said metal liner comprise a same material.

9. The interconnect structure of claim 1 , wherein said first and second conductive metal portions comprises Cu, Al, W, Co or alloys thereof.

10. The interconnect structure of claim 1 , wherein a topmost surface of said first conductive structure is coplanar with a topmost surface of said second conductive structure.

11. The interconnect structure of claim 4 , wherein a topmost surface of each of said first conductive metal portion and said second conductive metal portion is coplanar with a topmost surface of said second dielectric material portion.

12. The interconnect structure of claim 11 , wherein a topmost surface of each diffusion barrier portion is coplanar with said topmost surface of each of said first conductive metal portion, said second conductive metal portion and said second dielectric material portion.

13. The interconnect structure of claim 1 , wherein a portion of said metal liner located on said another sidewall surface and said bottom surface of said first conductive metal portion further extends onto the topmost surface of said first conductive metal portion.

14. The interconnect structure of claim 13 , wherein a portion of said metal liner located on said another sidewall surface and said bottom surface of said second conductive metal portion further extends onto the topmost surface of said second conductive metal portion.

15. The interconnect structure of claim 14 , further comprising a cap layer atop said metal liner located on the topmost surface first and second conductive metal portions and extending across said gap.

Assignees

• IBM

Inventors

• Yang Chih-Chao
• Cohen Stephan A
• Liniger Eric G

Classifications

• H10W20/0636

  the conductive members being on sidewalls · CPC title

• H10P50/283

  by chemical means · CPC title

• H10W20/4403

  based on metals, e.g. alloys, metal silicides (H10W20/4484 takes precedence) · CPC title

• H10W20/425 Primary

  Barrier, adhesion or liner layers · CPC title

• H10W20/081

  by forming openings in the dielectric parts · CPC title