Method of submicron metallization using electrochemical deposition of recesses including a first deposition at a first current density and a second deposition at an increased current density

• US 7,144,805 B2
• Filed: 07/01/2004
• Issued: 12/05/2006
• Est. Priority Date: 02/04/1998
• Status: Expired due to Fees

• Current Assignee: Semitool Incorporated (Applied Materials Incorporated)
• Original Assignee: Semitool Incorporated (Applied Materials Incorporated)
• Inventors: Ritzdorf, Thomas L., Graham, Lyndon W., Batz, Robert W. Jr., Fulton, Dakin, Chen, LinLin
• Primary Examiner(s): Brewster, William M.
• Application Number:
  US10/882,664
• Publication Number:
  US 20050051436A1
• Time in Patent Office: 887 Days
• Field of Search: 438/644, 438/672, 438/675
• US Class Current: 438/644
• CPC Class Codes: C25D 5/02 Electroplating of selected surface areas
• 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 5/18 Electroplating using modulated, pulsed or reversing current
• CPC Class Codes: C25D 5/50 by heat-treatment
• CPC Class Codes: C25D 5/605 Surface topography of the layers, e.g. rough, dendritic or nodular layers
• CPC Class Codes: C25D 5/611 Smooth layers
• 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: H01L 21/76883 Post-treatment or after-treatment of the conductive material

Abstract

Methods for depositing a metal into a micro-recessed structure in the surface of a microelectronic workpiece are disclosed. The methods are suitable for use in connection with additive free as well as additive containing electroplating solutions. In accordance with one embodiment, the method includes making contact between the surface of the microelectronic workpiece and an electroplating solution in an electroplating cell that includes a cathode formed by the surface of the microelectronic workpiece and an anode disposed in electrical contact with the electroplating solution. Next, an initial film of the metal is deposited into the micro-recessed structure using at least a first electroplating waveform having a first current density. The first current density of the first electroplating waveform is provided to enhance the deposition of the metal at a bottom of the micro-recessed structure. After this initial plating, deposition of the metal is continued using at least a second electroplating waveform having a second current density. The second current density of the second electroplating waveform is provided to assist in reducing the time required to substantially complete filling of the micro-recessed structure.

Claims

1. A method for depositing a metal into a micro-recessed structure in the surface of a microelectronic workpiece, the method comprising:

contacting the surface of the microelectronic workpiece with an electroplating solution in an electroplating cell, the electroplating cell including a cathode formed by the surface of the microelectronic workpiece and an anode;

electroplating to deposit a metal into the micro-recessed structure by applying a first electroplating waveform having a first current to the anode to enhance deposition of the metal at a bottom of the micro-recessed structure; and

further electroplating to further deposit the metal by changing the waveform applied to the anode to a second electroplating waveform having a second current to change the time required to at least substantially fill of the micro-recessed structure, wherein the second current is greater than the first current.

2. A method as claimed in claim 1 wherein the electroplating solution is substantially free of organic additives and has a high concentration of the metal that is to be electroplated.

3. A method as claimed in claim 1 wherein the metal that is to be plated is comprised of copper.

4. A method as claimed in claim 1 wherein the ratio between the first current density and the second current density is about 1:

10.

5. A method as claimed in claim 1 wherein the ratio between the first current density and the second current density is about 1:

8.

6. A method for depositing a metal into a micro-recessed structure in the surface of a microelectronic workpiece, the method comprising:

contacting the surface of the microelectronic workpiece with an electroplating solution in an electroplating cell, the electroplating cell including a cathode formed by the surface of the microelectronic workpiece and an anode;

depositing metal into the micro-recessed structure by applying a first electroplating waveform having a first current to the anode to enhance deposition of the metal in a bottom of the micro-recessed structure;

continuing to deposit the metal into the micro-recessed structure by applying a second electroplating waveform having a second current to the anode, the second current of the second electroplating waveform being different than the first current of the first electroplating waveform, wherein the second current is greater than the first current.

7. A method as claimed in claim 6 wherein the electroplating solution has a high concentration of metal ions or complexes of the metal that is to be deposited in the micro-recessed structure.

8. A method as claimed in claim 7 wherein the electroplating solution is substantially free of organic additives that are typically used as levelers or brighteners.

10. A method as claimed in claim 7 wherein the metal that is to be plated is comprised of copper.

11. A method as claimed in claim 8 wherein the metal that is to be plated is comprised of copper.

12. A method as claimed in claim 7 wherein the electroplating solution comprises a concentration of the metal that is between about 15 g/L and 36 g/L.

14. A method as claimed in claim 10 wherein the electroplating solution comprises a concentration of copper that is between about 15 g/L and 36 g/L.

15. A method as claimed in claim 11 wherein the electroplating solution comprises a concentration of copper that is between about 15 g/L and 36 g/L.

16. A method as claimed in claim 6 wherein the ratio between the first current density and the second current density is about 1:

10.

17. A method as claimed in claim 6 wherein the ratio between the first current density and the second current density is about 1:

8.

18. A method as claimed in claim 7 wherein the ratio between the first current density and the second current density is about 1:

10.

19. A method as claimed in claim 7 wherein the ratio between the first current density and the second current density is about 1:

8.

20. A method as claimed in claim 8 wherein the ratio between the first current density and the second current density is about 1:

10.

21. A method as claimed in claim 8 wherein the ratio between the first current density and the second current density is about 1:

8.

24. A method as claimed in claim 10 wherein the ratio between the first current density and the second current density is about 1:

10.

25. A method as claimed in claim 10 wherein the ratio between the first current density and the second current density is about 1:

8.

26. A method as claimed in claim 11 wherein the ratio between the first current density and the second current density is about 1:

10.

27. A method as claimed in claim 11 wherein the ratio between the first current density and the second current density is about 1:

8.

28. A method as claimed in claim 6 wherein the first electroplating waveform is a pulsed waveform.

29. A method as claimed in claim 7 wherein the first electroplating waveform is a pulsed waveform.

9. A method as claimed in 6 wherein the metal that is to be plated is comprised of copper.

13. A method as claimed in claim 9 wherein the electroplating solution comprises a concentration of copper that is between about 15 g/L and 36 g/L.

22. A method as claimed in claim 9 wherein the ratio between the first current density and the second current density is about 1:

10.

23. A method as claimed in claim 9 wherein the ratio between the first current density and the second current density is about 1:

8.