Metal on metal multiple patterning

Patent metadata

Field	Value
Publication number	US-11398378-B2
Application number	US-202017023853-A
Country	US
Kind code	B2
Filing date	Sep 17, 2020
Priority date	Sep 7, 2018
Publication date	Jul 26, 2022
Grant date	Jul 26, 2022

Abstract

The present disclosure relates to a structure which includes a first metal layer patterned as a mandrel, a dielectric spacer on the first metal layer, and a second metal layer on the dielectric spacer.

First claim

What is claimed:

1. A method, comprising:
patterning a first metal layer as a mandrel;
forming a dielectric spacer on the first metal layer;
forming a second metal layer on the dielectric spacer; and
forming a metal cap on the second metal layer.

2. The method of claim 1 , further comprising forming at least one airgap between patterned sections of the first metal layer.

3. The method of claim 2 , wherein the at least one airgap is surrounded by the dielectric spacer.

4. The method of claim 1 , further comprising forming nitrogen doped carbide on sections of the mandrel.

5. The method of claim 1 , further comprising forming a plurality of pinched off airgaps between sections of the mandrel by deposition of a dielectric material between sections of the mandrel.

6. The method of claim 1 , wherein the dielectric spacer comprises a low-k dielectric material.

7. The method of claim 1 , wherein the first metal layer is a same material as the second metal layer.

8. The method of claim 7 , wherein the first metal layer and the second metal layer comprises one of cobalt, ruthenium, nickel, aluminum, tungsten, and tantalum.

9. The method of claim 1 , wherein the first metal layer is a different material than the second metal layer.

10. The method of claim 1 , further comprising forming a plurality of cuts in the mandrel.

11. The method of claim 1 , wherein the metal cap comprises tantalum.

12. A method, comprising:
forming a metal mandrel with cuts along its longitudinal extent;
forming a metal layer on the metal mandrel;
forming a plurality of low-k dielectric spacers on sidewalls of the metal mandrel;
forming a metal cap on the metal layer; and
forming at least one airgap between sections of patterned metal in the metal mandrel,
wherein the at least one airgap is entirely surrounded by the low-k dielectric spacers.

13. The method of claim 12 , wherein the metal mandrel and the metal layer comprises cobalt.

14. The method of claim 12 , wherein the metal mandrel is a different material than the metal layer.

15. A method comprising:
forming a mandrel with cuts along its longitudinal extent;
forming a metal layer on the mandrel;
forming a plurality of low-k dielectric spacers on sidewalls of the mandrel; and
forming a metal cap on the metal layer,
wherein the mandrel is a different material than the metal layer.

16. The method of claim 15 , further comprising depositing a metal cap on the plurality of low-k dielectric spacers and which entirely surrounds the at least one airgap.

17. The method of claim 16 , further comprising forming nitrogen doped carbide on sections of the mandrel.

18. The method of claim 15 , further comprising forming at least one airgap which includes a plurality of pinched off airgaps formed by deposition of a low-k material between sections of the mandrel.

19. The method of claim 15 , wherein the mandrel is formed by patterning a film stack.

20. The method of claim 19 , wherein the mandrel comprises cobalt and the metal layer comprises copper.

Assignees

• Globalfoundries Inc

Inventors

• Chen Hsueh-Chung
• Srivastava Ravi P
• Ghosh Somnath
• Licausi Nicholas V
• Spooner Terry A
• Reidy Sean

Classifications

• H10P76/4085

  characterised by the processes involved to create the masks · CPC title

• H10W20/0633

  using subtractive patterning of the conductive members · CPC title

• H10W20/438

  Interconnections with multiple fill metals, e.g. having different metals in wide and narrow interconnections, or having different metals in vias and in trenches · CPC title

• H10W20/46

  comprising air gaps · CPC title

• H10W20/072

  of dielectric parts comprising air gaps · CPC title