Integrated deposition process for copper metallization

• US 6,566,259 B1
• Filed: 11/09/2000
• Issued: 05/20/2003
• Est. Priority Date: 12/02/1997
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Sun, Bingxi, Ding, Peijun, Hashim, Imran, Chin, Barry
• Primary Examiner(s): NGUYEN, HA T
• Application Number:
  US09/710,383
• Time in Patent Office: 922 Days
• Field of Search: 438/687, 438/632, 438/643, 438/627, 438/646, 438/653, 438/678, 438/676, 438/680, 438/685, 438/688
• US Class Current: 438/687
• CPC Class Codes: C23C 14/0641 Nitrides C23C14/0617 takes precedence
• CPC Class Codes: C23C 14/165 by cathodic sputtering
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 21/76876 for deposition from the gas phase, e.g. CVD
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/76882 Reflowing or applying of pressure to better fill the contact hole

Abstract

Metallization process sequences are provided for forming reliable interconnects including lines, vias and contacts. An initial barrier layer, such as Ta or TaN, is first formed on a patterned substrate followed by seed layer formed using high density plasma PVD techniques. The structure is then filled using either 1) electroplating, 2) PVD reflow, 3) CVD followed by PVD reflow, or 4) CVD.

Claims

1. A process for forming an interconnect on a patterned substrate, comprising:

depositing a barrier layer on the substrate in a first high density physical vapor deposition chamber;

depositing a seed layer on the barrier layer in a second high density physical vapor deposition chamber; and

depositing a first metal layer on the seed layer, wherein the seed layer and the first metal layer comprise the same material.

2. The process of claim 1, wherein the first metal layer is deposited by electroplating.

3. The process of claim 2, wherein the barrier layer comprises tantalum, tantalum nitride, or combinations thereof, and the seed layer and the first metal layer comprise copper.

4. The process of claim 1, wherein the first metal layer is deposited in a physical vapor deposition reflow chamber at a substrate temperature between about 200°

C. and about 450°

C.

5. The process of claim 4, wherein the barrier layer comprises tantalum, tantalum nitride, or combinations thereof, and the seed layer and the first metal layer comprise copper.

6. The process of claim 1, wherein the first metal layer is deposited by chemical vapor deposition.

7. The process of claim 6, further comprising depositing a second metal layer over the first metal layer at a substrate temperature between about 100°

C. and about 450°

C. by physical vapor deposition.

8. The process of claim 7, wherein the barrier layer comprises tantalum, tantalum nitride, or combinations thereof, and the seed layer, the first metal layer, and the second metal layer comprise copper.

9. The process of claim 6, wherein the barrier layer comprises tantalum, tantalum nitride, or combinations thereof, and the seed layer and the first metal layer comprise copper.

10. The process of claim 1, wherein depositing the barrier layer comprises delivering a bias between about 0.5 kW and about 5 kW to a target, delivering RF power between about 0.5 kW and about 3 kW to a source coil, and delivering a bias between about 0 W and about 500 W to the substrate.

11. The process of claim 1, wherein depositing the seed layer comprises delivering a bias between about 0.5 kW and about 5 kW to a target, delivering RF power between about 0.5 kW and about 3 kW to a source coil, and delivering a bias between about 0 W and about 500 W to the substrate.

12. The process of claim 1, wherein the barrier layer and the seed layer are deposited in an integrated system.

13. A process for forming an interconnect on a patterned substrate, comprising:

depositing a barrier layer on the substrate by delivering a bias between about 0.5 kW and about 5 kW to a target and delivering a bias between about 0 W and about 500 W to the substrate and establishing a pressure of about 45 mTorr or less in a first high density physical vapor deposition chamber;

depositing a seed layer on the barrier layer by delivering a bias between about 0.5 kW and about 5 kW to a target and delivering a bias between about 0 W and about 500 W to the substrate and establishing a pressure of about 45 mTorr or less in a second high density physical vapor deposition chamber; and

depositing a first metal layer on the seed layer, wherein the seed layer and the first metal layer comprise the same material.

14. The process of claim 13, wherein the first metal layer is deposited by electroplating.

15. The process of claim 13, wherein the first metal layer is deposited in a physical vapor deposition reflow chamber at a substrate temperature between about 200°

C. and about 450°

C.

16. The process of claim 13, wherein the first metal layer is deposited by chemical vapor deposition.

17. The process of claim 16, further comprising depositing a second metal layer on the first metal layer at a substrate temperature between about 100°

C. and about 450°

C. by physical vapor deposition.

18. The process of claim 17, wherein the barrier layer comprises tantalum, tantalum nitride, or combinations thereof, and the seed layer, the first metal layer, and the second metal layer comprise copper.

19. The process of claim 13, wherein the barrier layer comprises tantalum, tantalum nitride, or combinations thereof, and the seed layer and the first metal layer comprise copper.

20. The process of claim 13, wherein depositing the barrier layer further comprises delivering RF power between about 0.5 kW and about 3 kW to a source coil.

21. The process of claim 13, wherein depositing the seed layer further comprises delivering RF power between about 0.5 kW and about 3 kW to a source coil.

22. The process of claim 13, wherein the barrier layer and the seed layer are deposited in an integrated system.

23. A process for forming an interconnect, comprising:

depositing a barrier layer on the substrate, wherein the barrier layer is selected from the group of tantalum, tantalum nitride, and combinations thereof, in a first high density physical vapor deposition chamber;

depositing a copper seed layer on the barrier layer in a second high density physical vapor deposition chamber; and

depositing a copper layer on the copper seed layer by electroplating.

24. The process of claim 23, wherein depositing the barrier layer comprises delivering a bias between about 0.5 kW and about 5 kW to a target and delivering a bias between about 0 W and about 500 W to the substrate disposed in the first high density physical vapor deposition chamber.

25. The process of claim 24, wherein depositing the barrier layer further comprises delivering RF power between about 0.5 kW and about 3 kW to a source coil disposed in the first high density physical vapor deposition chamber.

26. The process of claim 23, wherein depositing the copper seed layer comprises delivering a bias between about 0.5 kW and about 5 kW to a target and delivering a bias between about 0 W and about 500 W to the substrate disposed in the first high density physical vapor deposition chamber.

27. The process of claim 26, wherein depositing the copper seed layer further comprises delivering RF power between about 0.5 kW and about 3 kW to a source coil disposed in the first high density physical vapor deposition chamber.