Method to improve copper electrochemical deposition

• US 20050045485A1
• Filed: 09/03/2003
• Published: 03/03/2005
• Est. Priority Date: 09/03/2003
• Status: Abandoned Application

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Shih, Chien-Hsueh, Ko, Ting-Chu, Tsai, Minghsing
• Application Number:
  US10/654,523
• Publication Number:
  US 20050045485A1
• Time in Patent Office: Days
• US Class Current: 205/123
• CPC Class Codes: C25D 15/00 Electrolytic or electrophoretic production of coatings containing embedded materials, e.g. particles, whiskers, wires
• CPC Class Codes: C25D 3/38 of copper
• CPC Class Codes: C25D 5/10 Electroplating with more than one layer of the same or of different metals for bearings C25D7/10
• CPC Class Codes: C25D 7/123 Semiconductors first coated with a seed layer or a conductive layer
• CPC Class Codes: H01L 21/2885 using an external electrical current, i.e. electro-deposition
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H05K 3/423 characterised by electroplating method

Abstract

A method for reducing or avoiding copper layer pitting in a copper electrochemical deposition process to improve deposition uniformity including providing a substrate for carrying out at least a first copper electroplating process; providing a copper electroplating solution including a deforming (antiforming) agent wherein the antiforming (deforming) agent includes at least one alkylene monomer; and, carrying out at least a first copper electroplating process to deposit at least a first copper layer.

Claims

1. A method for reducing or avoiding copper layer pitting in a copper electrochemical deposition process to improve deposition uniformity comprising the steps of:

providing a substrate for carrying out at least a first copper electroplating process;

providing a copper plating solution comprising a deforming (antiforming) agent wherein the deforming agent comprises at least one alkylene monomer; and

,

carrying out at least a first copper electroplating process to deposit at least a first copper layer.

2. The method of claim 1, wherein the antiforming (deforming) agent is selected from the group consisting of polyalkylene glycols, polyalkylene glycol ethers, polyalkylene oxide copolymers, and amine based polyalkylene oxide copolymers.

3. The method of claim 2, wherein the antiforming (deforming) agent comprises an alkylene monomer selected from the group consisting of ethylene, propylene and butylene.

4. The method of claim 2, wherein the polyalkylene oxide copolymers and amine based polyalkylene oxide copolymers comprise oxide groups selected from the group consisting of ethylene oxide, propylene oxide, and butylene oxide.

5. The method of claim 1, wherein the concentration of the antiforming (deforming) agent is between about 5 ppm and about 1000 ppm of copper plating solution.

6. The method of claim 1, wherein the concentration of the antiforming (deforming) agent is between about 50 ppm and about 500 ppm of copper plating solution.

7. The method of claim 1, wherein the at least a first copper electroplating process is carried out at a temperature from about 0°

C. to about 50°

C.

8. The method of claim 1, wherein the copper plating solution further comprises a copper salt.

9. The method of claim 8, the copper salt is selected from the group consisting of copper sulfates, copper acetates, and cupric nitrates.

10. The method of claim 1, wherein the substrate comprises a semiconductor process wafer comprising an opening extending through at least one dielectric insulator and a copper seed layer lining the opening the opening.

11. The method of claim 10, wherein the at least a first copper electroplating process is carried out to fill a portion of the opening to line less than about 75 percent of the smallest critical dimension.

12. The method of claim 11, wherein the opening is one of a damascene and dual damascene opening.

13. The method of claim 11, wherein the smallest critical dimension comprises a via opening diameter.

14. The method of claim 12, wherein a via opening portion comprises an aspect ratio of greater than about 4 to 1 and a diameter of less than about 0.15 microns.

15. The method of claim 11, further comprising a second copper electroplating process to deposit a second copper layer to fill the opening.

16. The method of claim 15 wherein the second copper electroplating process comprises the addition of at least one additive to the copper plating solution selected from the group comprising suppressors, brighteners, levelers, and the antiforming (deforming) agent.

17. The method of claim 16, wherein the second copper electroplating process is carried out at a temperature from about 5°

C. to about 10°

C. lower than the first copper electroplating process.

18. The method of claim 15, wherein the second copper electroplating process comprises at least one period of electropolishing a portion of the second copper layer.

19. A method for improving a copper electroplating process for filling high aspect ratio openings to reduce or avoid pitting defects comprising the steps of:

providing a semiconductor process wafer comprising a via opening extending through a thickness of at least one dielectric insulating layer including an uppermost copper seed layer lining the via opening;

providing a copper plating solution for carrying out at least a first copper electroplating process over the copper seed layer wherein the copper plating solution includes at least one copper salt, an electrolyte, and at least one deforming (antiforming) agent selected from the group consisting of polyalkylene glycols, polyalkylene glycol ethers, polyalkylene oxide copolymers, and amine base polyalkylene oxide copolymers;

carrying out the at least a first copper electroplating process to blanket deposit a first copper layer to cover the copper seed layer; and

,

carrying out at least a second copper electroplating process to blanket deposit at least a second copper layer comprising the addition of additives to the copper plating solution selected from the group consisting of suppressors, brighteners, levelers, and the at least one deforming (antiforming) agent.

20. The method of claim 19, wherein the at least one deforming (antiforming) agent comprises at least one alkylene monomer selected from the group consisting of ethylene, propylene, and butylene.

21. The method of claim 19, wherein the at least one deforming (antiforming) agent is between about 50 ppm and about 500 ppm of copper plating solution.

22. The method of claim 19, wherein the first copper electroplating process is carried out at a temperature from about 0°

C. to about 50°

C.

23. The method of claim 19, wherein the at least a first copper electroplating process is carried out at a temperature from about 10°

C. to about 30°

C.

24. The method of claim 19, wherein the at least a second copper electroplating process is carried out at a temperature about 5°

C. to about 10°

C. lower than the first copper electroplating process.

25. The method of claim 19, wherein the at least a first copper electroplating process is carried out to substantially conformally fill from about 25 to about 75 percent of the via opening volume.

26. The method of claim 19, wherein the via opening diameter is less than about 0.25 microns.

27. The method of claim 19, wherein the second copper electroplating process comprises at least one period of electropolishing a portion of the second copper layer.

28. A copper electroplating solution for carrying out an electroplating process comprising:

an antiforming (deforming) agent comprising an alkylene containing monomer.

29. The copper electroplating solution of claim 28, further comprising an electrolyte and at least one copper salt.

30. The copper electroplating solution of claim 28, wherein the alkylene monomer is selected from the group consisting of ethylene, propylene, and butylene.

31. The copper electroplating solution of claim 28, wherein the antiforming (deforming) agent comprises a constituent selected from the group consisting of is selected from the group consisting of polyalkylene glycols, polyalkylene glycol ethers, polyalkylene oxide copolymers, and amine based polyalkylene oxide copolymers.

32. The copper electroplating solution of claim 31, wherein the polyalkylene oxide copolymers and amine based polyalkylene oxide copolymers comprise oxide groups selected from the group consisting of ethylene oxide, propylene oxide, and butylene oxide.

33. The copper electroplating solution of claim 28, further comprising additives selected from the group consisting of suppressors, brighteners, and levelers.

34. The copper electroplating solution of claim 28, wherein the antiforming (deforming) agent is provided at a concentration of from about 5 ppm to about 1000 ppm.

35. The copper electroplating solution of claim 28, wherein the antiforming (deforming) agent is provided at a concentration of from about 50 ppm to about 500 ppm.