Methods and apparatus for forming dual metal interconnects

Patent metadata

Field	Value
Publication number	US-11075165-B2
Application number	US-201916516817-A
Country	US
Kind code	B2
Filing date	Jul 19, 2019
Priority date	Jul 19, 2019
Publication date	Jul 27, 2021
Grant date	Jul 27, 2021

Abstract

Methods and apparatus for creating a dual metal interconnect on a substrate. In some embodiments, a first liner of a first nitride material is deposited into at least one 1× feature and at least one wider than 1× feature, the first liner has a thickness of less than or equal to approximately 12 angstroms; a second liner of a first metal material is deposited into the at least one 1× feature and at least one wider than 1× feature; the first metal material is reflowed such that the at least one 1× feature is filled with the first metal material and the at least one wider than 1× feature remains unfilled with the first metal material; a second metal material is deposited on the first metal material, and the second metal material is reflowed such that the at least one wider than 1× feature is filled with the second metal material.

First claim

The invention claimed is:

1. A method for creating a dual metal interconnect, comprising:
depositing a first liner of a first nitride material into at least one 1X feature and at least one wider than 1X feature, the first liner has a thickness of less than or equal to approximately 12 angstroms, wherein X is a minimum feature width;
depositing a second liner of a first metal material into the at least one 1X feature and at least one wider than 1X feature;
reflowing the first metal material such that the at least one 1X feature is filled with the first metal material and the at least one wider than 1X feature remains partially filled;
depositing a second metal material on the first metal material; and
reflowing the second metal material such that the at least one wider than 1X feature is filled with the second metal material.

2. The method of claim 1 , further comprising
polishing the second metal material;
polishing the first metal material and the second metal material with an electro-chemical balanced solution for dual metal polishing; and
over polishing the first metal material and the second metal material with a corrosion inhibitor and pH control solution.

3. The method of claim 1 , further comprising:
pre-cleaning the at least one 1X feature and the at least one wider than 1X feature prior to depositing the first liner.

4. The method of claim 1 , further comprising:
depositing the first liner to a thickness of approximately 5 angstroms to approximately 12 angstroms.

5. The method of claim 1 , further comprising:
depositing the second liner to a thickness of approximately 40 angstroms to approximately 60 angstroms.

6. The method of claim 1 , further comprising:
reflowing the first metal material by depositing additional first metal material and performing a hydrogen gas anneal or by performing an anneal of the first metal material already deposited.

7. The method of claim 1 , further comprising:
depositing a second metal seed material on the first metal material prior to depositing the second metal material, the second metal seed material composed of at least the second metal material doped with manganese.

8. The method of claim 1 , further comprising:
depositing a third liner of a second nitride material into the at least one wider than 1X feature after reflowing the first metal material, the third liner has a thickness of approximately 5 angstroms to approximately 10 angstroms.

9. The method of claim 1 , further comprising:
performing electroplating of the second metal material instead of depositing and reflowing the second metal material.

10. The method of claim 1 , further comprising:
etching the first metal material in the at least one wider than 1X feature after reflowing the first metal material.

11. The method of claim 10 , further comprising:
depositing a third liner of a second nitride material after etching and without an air break after etching.

12. The method of claim 11 , wherein the first nitride material or the second nitride material is tantalum nitride or titanium nitride.

13. The method of claim 1 , wherein one of the at least one 1X feature has a height different from one of the at least one wider than 1X feature.

14. The method of claim 1 , wherein the first metal material is cobalt, ruthenium, molybdenum, nickel, rhodium, or iridium.

15. The method of claim 1 , wherein the second metal material is copper or aluminum.

16. An architecture for interconnecting structures on a substrate, comprising:
at least one 1X feature formed with a first barrier layer with a thickness of approximately 5 angstroms to approximately 12 angstroms and filled with a conductive material having low diffusivity, high electromigration resistance, low scattering, and low resistivity at critical dimensions (CD) of approximately 15 nm or less, where X is a minimum feature width; and
at least one 3X to 5 X feature formed with the first barrier layer and partially filled with the conductive material used in forming the at least one 1X feature and filled with a copper-based material with low resistivity.

17. The architecture of claim 16 , wherein the first barrier layer is tantalum nitride or titanium nitride and the conductive material is cobalt, ruthenium, or molybdenum.

18. The architecture of claim 16 , wherein the at least one 3X to 5 X feature has a second barrier layer formed by a tantalum nitride flash between the conductive material and the copper-based material, wherein the copper-based material is a copper manganese alloy.

Assignees

• Applied Materials Inc

Inventors

• Parikh Suketu A
• Tao Rong
• Shaviv Roey
• Lee Joung Joo
• Ganguli Seshadri
• Pethe Shirish
• Gage David
• Tang Jianshe
• Stolfi Michael A

Classifications

• H10W20/0552

  by diffusing metallic dopants to react with dielectrics · CPC title

• H10W20/0595

  by using multiple deposition steps separated by etching steps · CPC title

• H10W20/4437

  the principal metal being a transition metal · CPC title

• H10P72/0468

  comprising a chamber adapted to a particular process · CPC title

• H10P70/234

  the processing being the formation of vias or contact holes · CPC title