Electroless deposition of continuous platinum layer using complexed Co2+ metal ion reducing agent

Patent metadata

Field	Value
Publication number	US-9499913-B2
Application number	US-201414243793-A
Country	US
Kind code	B2
Filing date	Apr 2, 2014
Priority date	Apr 2, 2014
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

A solution for electroless deposition of platinum is provided. The solution comprises Co 2+ ions, Pt 4+ ions, and amine ligands. A ratio of Co 2+ to Pt 4+ ion is between 100:1 and 2:1. The solution allows for electroless deposition of platinum without requiring high temperatures and high pH. The solution allows for the deposition of a pure platinum layer.

First claim

What is claimed is:

1. A solution for electroless deposition of platinum, comprising:
Co 2+ ions;
Pt 4+ ions; and
amine ligands.

2. The solution, as recited in claim 1 , wherein the solution has a pH between 6 and 11, inclusive and a ratio of Co 2+ to Pt 4+ ion is between 100:1 and 2:1.

3. The solution, as recited in claim 2 , further comprising Cl − ions.

4. The solution, as recited in claim 3 , wherein the concentration of Co 2+ ions is 1-500 mM.

5. The solution, as recited in claim 1 , wherein the solution is boron, phosphorus, hydrazine, and formaldehyde free.

6. A method for providing an electroless plating of a platinum containing layer, comprising:
providing a Co 2+ concentrated stock solution;
providing a Pt 4+ concentrated stock solution;
combining a flow from the Co 2+ concentrated stock solution with a flow from the Pt 4+ concentrated stock solution and water to provide a mixed electrolyte solution of the Co 2+ concentrated stock solution and the Pt 4+ concentrated stock solution; and
exposing a substrate to the mixed electrolyte solution of the Co 2+ concentrated stock solution and the Pt 4+ concentrated stock solution.

7. The method, as recited in claim 6 , wherein exposing the substrate to the mixed electrolyte solution of the Co 2+ concentrated stock solution and the Pt 4+ concentrated stock solution, comprises:
providing a solution temperature between 10° to 40° C., inclusive; and
providing a pH of between 6 and 11, inclusive.

8. The method, as recited in claim 7 , wherein exposing the substrate to the mixed electrolyte solution of the Co 2+ concentrated stock solution and the Pt 4+ concentrated stock solution provides Co 2+ with a concentration between 1-500 mM.

9. The method, as recited in claim 8 , further comprising disposing the mixed electrolyte solution.

10. The method, as recited in claim 9 , wherein the platinum containing layer is 99.9% pure platinum.

11. The method, as recited in claim 8 , further comprising reactivating the mixed electrolyte solution.

12. The method, as recited in claim 8 , wherein the Co 2+ concentrated stock solution comprises a solution of CoSO 4 .

13. The method, as recited in claim 12 , wherein the Pt 4+ concentrated stock solution comprises a solution of H 2 PtCl 6 and amine ligands.

14. The method, as recited in claim 13 , wherein the Co 2+ concentrated stock solution further comprises amine ligands.

15. The method, as recited in claim 14 , wherein the Pt 4+ concentrated stock solution has a shelf life of over a year.

16. The method, as recited in claim 15 , wherein the Co2+ concentrated stock solution has a shelf life of over a year.

17. The method, as recited in claim 14 , wherein the mixed electrolyte solution is boron, phosphorus, hydrazine, and formaldehyde free.

18. The method, as recited in claim 6 , wherein the mixed electrolyte solution is boron, phosphorus, hydrazine, and formaldehyde free.

19. A method for providing an electroless plating of a platinum layer, comprising:
providing a solution for electroless deposition of platinum, comprising:
Co 2+ ions;
Pt 4+ ions; and
amine ligands; and

exposing a substrate to the solution for electroless deposition of platinum.

20. The method, as recited in claim 19 , wherein the providing the solution, provides the solution at a pH of between 6 and 11, inclusive, and at a temperature between 10° to 40° C., inclusive and, wherein a ratio of Co 2+ to Pt 4+ ion is between 100:1 to 2:1.

Assignees

• Lam Res Corp

Inventors

• Norkus Eugenijus
• Stankeviciene Ina
• Jagminiene Aldona
• Tamasauskaite-Tamasiunaite Loreta
• Joi Aniruddha
• Dordi Yezdi

Classifications

• H10P14/46

  using a liquid · CPC title

• H10W20/037

  the barrier, adhesion or liner layers being on top of a main fill metal · CPC title

• C23C18/166

  with two steps starting with addition of reducing agent followed by metal deposition · CPC title

• C23C18/1683

  Control of electrolyte composition, e.g. measurement, adjustment (regeneration of bath C23C18/1617) · CPC title

• C23C18/168

  Control of temperature, e.g. temperature of bath, substrate · CPC title