Metal deposition process with pre-cleaning before electrochemical deposition

• US 20040118697A1
• Filed: 10/01/2003
• Published: 06/24/2004
• Est. Priority Date: 10/01/2002
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Wen+, Mei, Herchen, Harald, Mori, Glen T., Mostovoy, Roman M.
• Application Number:
  US10/676,208
• Publication Number:
  US 20040118697A1
• Time in Patent Office: Days
• US Class Current: 205/215
• CPC Class Codes: C23C 14/58 After-treatment
• CPC Class Codes: C25D 5/34 Pretreatment of metallic surfaces to be electroplated
• CPC Class Codes: H01L 21/02052 Wet cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/321 After treatment
• CPC Class Codes: H01L 21/76856 by treatment in plasmas or gaseous environments, e.g. nitriding a refractory metal liner
• CPC Class Codes: H01L 21/76861 Post-treatment or after-treatment not introducing additional chemical elements into the layer
• CPC Class Codes: H01L 21/76862 Bombardment with particles, e.g. treatment in noble gas plasmas; UV irradiation
• CPC Class Codes: H01L 21/76873 for electroplating

Abstract

A metal seed layer on a substrate is pre-cleaned prior to formation of an electrochemically deposited metal fill layer. A liquid-based pre-clean may include, for example, an agitated rinse, an etchant solution, a surfactant solution and/or a solvent-solution to remove organic and/or other contaminants from the metal seed layer. A dry pre-clean may utilize, for example, a hydrogen and/or an oxygen plasma to remove contaminants and/or reduce a metal oxide of the seed layer. In at least one embodiment, the reduction of the metal oxide may occur at a pressure in excess of 0.1 atmosphere.

Claims

1. A method comprising:

providing a substrate having a metal seed layer;

applying an agitated rinse to the metal seed layer; and

depositing a metal fill layer on the rinsed metal seed layer by electrochemical deposition.

2. The method of claim 1, wherein the metal seed layer comprises a copper seed layer.

3. The method of claim 1, wherein providing a substrate having a metal seed layer comprises depositing the metal seed layer on the substrate by physical vapor deposition.

4. The method of claim 1, wherein both the applying step and the depositing step are performed in the same chamber.

5. A method comprising:

providing a substrate having a metal seed layer;

exposing the metal seed layer to a liquid that includes a surfactant; and

depositing a metal fill layer on the metal seed layer by electrochemical deposition.

6. The method of claim 5, wherein the metal seed layer comprises a copper seed layer.

7. The method of claim 5, wherein providing a substrate having a metal seed layer comprises depositing the metal seed layer by physical vapor deposition.

8. The method of claim 5, wherein both the exposing step and the depositing step are performed in the same chamber.

9. The method of claim 5, further comprising:

rinsing the metal seed layer after the exposing step.

10. A method comprising:

providing a substrate having a metal seed layer;

exposing the metal seed layer to an organic solvent; and

depositing a metal fill layer on the metal seed layer by electrochemical deposition.

11. The method of claim 10, wherein the metal seed layer comprises a copper seed layer.

12. The method of claim 10, wherein providing a substrate having a metal seed layer comprises depositing the metal seed layer by physical vapor deposition.

13. The method of claim 10, wherein both the exposing step and the depositing step are performed in the same chamber.

14. The method of claim 10, further comprising:

rinsing the metal seed layer after the exposing step.

15. A method comprising:

providing a substrate having a metal seed layer;

exposing the metal seed layer to activated hydrogen at a pressure of at least 0.1 atmosphere; and

depositing a metal fill layer on the metal seed layer by electrochemical deposition.

16. The method of claim 15, wherein the exposing step is performed at substantially atmospheric pressure.

17. The method of claim 15, wherein the exposing step includes exposing the metal seed layer to a plasma that includes hydrogen.

18. The method of claim 15, wherein the metal seed layer comprises a copper seed layer.

19. The method of claim 15, wherein providing a substrate having a metal seed layer comprises depositing the metal seed layer on the substrate by physical vapor deposition.

20. The method of claim 15, further including exposing the metal seed layer to activated oxygen.

21. A method comprising:

providing a substrate having a metal seed layer;

exposing the metal seed layer to an oxidant solution so as to form an oxidized surface layer on the metal seed layer; and

depositing a metal fill layer on the metal seed layer by electrochemical deposition.

22. The method of claim 21, wherein the oxidant solution comprises hydrogen peroxide.

23. The method of claim 22, wherein the oxidant solution comprises a concentration of hydrogen peroxide of between about 0.1 percent and 6 percent.

24. The method of claim 21, wherein the metal seed layer is exposed to the oxidant solution for about one minute or less.

25. The method of claim 21, wherein the oxidized surface layer has a thickness of about 100 angstroms or less.

26. The method of claim 21, wherein the oxidized surface layer is adapted to reduce an occurrence of gas bubbles forming on the metal seed layer upon immersion of the metal seed layer in an electrolyte solution of an electrochemical deposition bath.

27. The method of claim 21, wherein the oxidized surface layer is adapted to increase wettability of the metal seed layer.