Multiple seed layers for metallic interconnects

• US 20010005056A1
• Filed: 12/04/2000
• Published: 06/28/2001
• Est. Priority Date: 10/02/1999
• Status: Active Grant

• Current Assignee: Uri Cohen
• Original Assignee: Uri Cohen
• Inventors: Cohen, Uri
• Granted Patent: US 6,518,668 B2
• Time in Patent Office: Days
• US Class Current: 257/751
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 2221/1089 Stacks of seed layers

Abstract

One embodiment of the present invention is a multiple seed layer structure for making metallic interconnect including: (a) a patterned insulating layer on a substrate, the patterned insulating layer including at least one opening and a field surrounding the at least one opening; (b) a barrier layer disposed over the field and inside surfaces of the at least one opening; (c) a first seed layer disposed over the barrier layer using a first deposition technique; (d) a second seed layer disposed over the first seed layer using a second deposition technique, the first and second deposition techniques being different, one producing a substantially conformal seed layer and the other producing a substantially non-conformal seed layer; and (e) an electroplated metallic layer disposed over the second seed layer, the electroplated metallic layer including a material selected from a group consisting of Cu, Ag, or alloys including one or more of these metals.

Claims

1. A multiple seed layer structure used to fabricate devices, said multiple seed layer structure comprises:

a substrate;

a patterned insulating layer formed on said substrate, said patterned insulating layer including at least one opening and a top field surface surrounding said at least one opening;

a barrier layer disposed over said patterned insulating layer including over inside bottom and sidewalls surfaces of the at least one opening;

a first seed layer disposed over the barrier layer, said first seed layer is formed by a first deposition technique;

a second seed layer disposed over the first seed layer, said second seed layer is formed by a second deposition technique, the first and second deposition techniques being different; and

an electroplated metallic layer disposed over the second seed layer, wherein the electroplated metallic layer comprises a material selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.

2. The multiple seed layer structure of

claim 1

wherein the first deposition technique comprises a substantially conformal deposition technique and the second deposition technique comprises a substantially non-conformal deposition technique.

3. The multiple seed layer structure of

claim 2

wherein said second seed layer being thicker than said first seed layer over the field.

4. The multiple seed layer structure of

claim 1

wherein the first deposition technique comprises a chemical vapor deposition or electroless deposition technique and the second deposition technique comprises a physical vapor deposition technique.

5. The multiple seed layer structure of

claim 4

wherein the first deposition technique comprises a chemical vapor deposition technique.

6. The multiple seed layer structure of

claim 4

wherein said second seed layer being thicker than said first seed layer over the field.

7. The multiple seed layer structure of

claim 1

wherein the first deposition technique comprises a substantially non-conformal deposition technique and the second deposition technique comprises a substantially conformal deposition technique.

8. The multiple seed layer structure of

claim 7

wherein said first seed layer being thicker than said second seed layer over the field.

9. The multiple seed layer structure of

claim 1

wherein the first deposition technique comprises a physical vapor deposition technique and the second deposition technique comprises a chemical vapor deposition technique or electroless deposition technique.

10. The multiple seed layer structure of

claim 9

wherein the second deposition technique comprises a chemical vapor deposition technique.

11. The multiple seed layer structure of

claim 9

wherein said first seed layer being thicker than said second seed layer over the field.

12. The multiple seed layer structure of

claim 1

wherein the electroplated metallic layer comprises Cu.

13. The multiple seed layer structure of

claim 1

wherein the electroplated metallic layer comprises Ag.

15. The multiple seed layer structure of

claim 1

wherein the first and second seed layers comprise Cu.

16. The multiple seed layer structure of

claim 1

wherein the barrier layer is selected from a group consisting of Ta, TaN_X, Cr, CrN_X, Ti, TiN_X, W, WN_X, or alloys comprising one or more of these materials.

17. The multiple seed layer structure of

claim 1

wherein the barrier layer is deposited by a chemical vapor deposition technique.

18. The multiple seed layer structure of

claim 1

wherein the barrier layer is deposited by a physical vapor deposition technique.

19. The multiple seed layer structure of

claim 1

wherein the first deposition technique comprises a substantially conformal deposition technique and the second deposition technique comprises a substantially non-conformal deposition technique and further comprising at least one additional seed layer deposited over the second seed layer prior to electroplating.

20. The multiple seed layer structure of

claim 1

wherein the first deposition technique comprises a substantially conformal deposition technique and the second deposition technique comprises a substantially non-conformal deposition technique and further comprising at least one additional seed layer deposited under the first seed layer.

21. The multiple seed layer structure of

claim 19

wherein the at least one additional seed layer is formed by a substantially conformal deposition technique.

22. The multiple seed layer structure of

claim 20

wherein the at least one additional seed layer is formed by a substantially non-conformal deposition technique.

23. The multiple seed layer structure of

claim 21

wherein the first deposition technique comprises a chemical vapor deposition technique, the second deposition technique comprises a physical vapor deposition technique, and the at least one additional seed layer is formed by a chemical vapor deposition technique.

24. The multiple seed layer structure of

claim 22

wherein the at least one additional seed layer is formed by a physical vapor deposition technique.

25. The multiple seed layer structure of

claim 1

wherein the first deposition technique comprises a substantially non-conformal deposition technique and the second deposition technique comprises a substantially conformal deposition technique and further comprising at least one additional seed layer formed over the second seed layer prior to electroplating.

26. The multiple seed layer structure of

claim 25

wherein the at least one additional seed layer is formed by a substantially non-conformal deposition technique.

27. The multiple seed layer structure of

claim 26

wherein the first deposition technique comprises a physical vapor deposition technique, the second deposition technique comprises a chemical vapor deposition technique, and the at least one additional seed layer is formed by a physical vapor deposition technique.

28. A metallic interconnect fabricated by using the multiple seed layer structure of

claim 1

, wherein the electroplated metallic layer overlying the opening and overlying the field, and the first and second seed layers overlying the field, and the barrier layer overlying the field, are substantially removed by a removal technique, said removal technique comprises one or more of a mechanical polishing technique, a chemical mechanical polishing technique, a wet etching technique, and a dry etching technique.

29. The metallic interconnect of

claim 28

wherein the first deposition technique comprises a substantially conformal deposition technique and the second deposition technique comprises a substantially non-conformal deposition technique.

30. The metallic interconnect of

claim 29

wherein said second seed layer being thicker than said first seed layer over the field.

31. The metallic interconnect of

claim 28

wherein:

the first deposition technique comprises a chemical vapor deposition (CVD) technique or an electroless technique; and

the second deposition technique comprises a physical vapor deposition (PVD) technique.

32. The metallic interconnect of

claim 31

wherein the first deposition technique comprises a chemical vapor deposition (CVD) technique.

33. The metallic interconnect of

claim 31

wherein said second seed layer being thicker than said first seed layer over the field.

34. The metallic interconnect of

claim 28

wherein the first deposition technique comprises a substantially non-conformal deposition technique and the second deposition technique comprises a substantially conformal deposition technique.

35. The metallic interconnect of

claim 34

wherein said first seed layer being thicker than said second seed layer over the field.

36. The metallic interconnect of

claim 28

wherein:

the first deposition technique comprises a physical vapor deposition (PVD) technique; and

the second deposition technique comprises a chemical vapor deposition (CVD) or an electroless technique.

37. The metallic interconnect of

claim 36

wherein the second deposition technique comprises a chemical vapor deposition (CVD) technique.

38. The metallic interconnect of

claim 36

wherein said first seed layer being thicker than said second seed layer over the field.

39. The metallic interconnect of

claim 29

wherein the first seed layer and the second seed layer comprise a material selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.

40. The metallic interconnect of

claim 34

wherein the first seed layer and the second seed layer comprise a material selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.

41. The metallic interconnect of

claim 29

wherein the first and second seed layers comprise Cu.

42. The metallic interconnect of

claim 34

wherein the first and second seed layers comprise Cu.

43. The metallic interconnect of

claim 33

wherein the first seed layer has a thickness in a range of about 50 Å

to about 500 Å

over the field and the second seed layer has a thickness in a range of about 100 Å

to about 2,000 Å

over the field.

44. The metallic interconnect of

claim 33

wherein the first seed layer has a thickness in a range of about 100 Å

to about 300 Å

over the field and the second seed layer has a thickness in a range of about 300 Å

to about 1,000 Å

over the field.

45. The metallic interconnect of

claim 38

wherein the first seed layer has a thickness in a range of about 100 Å

to about 2,000 Å

over the field and the second seed layer has a thickness in a range of about 50 Å

to about 500 Å

over the field.

46. The metallic interconnect of

claim 38

wherein the first seed layer has a thickness in a range of about 300 Å

to about 1,000 Å

over the field and the second seed layer has a thickness in a range of about 100 Å

to about 300 Å

over the field.

47. The metallic interconnect of

claim 28

wherein the barrier layer is selected from a group consisting of Ta, TaN_X, Cr, CrN_X, Ti, TiN_X, W, WN_X, or alloys comprising one or more of these materials.

48. The metallic interconnect of

claim 28

wherein the barrier layer is deposited by a chemical vapor deposition technique.

49. The metallic interconnect of

claim 28

wherein the barrier layer is deposited by a physical vapor deposition technique.

50. The metallic interconnect of

claim 28

wherein the barrier layer has a thickness in a range of about 30 Å

to about 500 Å

.

51. The metallic interconnect of

claim 28

wherein the barrier layer has a thickness in a range of about 50 Å

to about 300 Å

.

14. The multiple seed layer structure of claim I wherein the first and second seed layers comprise a material selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.

52. A multiple seed layer structure used to fabricate copper interconnects, said multiple seed layer structure comprising:

a patterned insulating layer formed on a substrate, the patterned insulating layer including at least one opening and a field surrounding the at least one opening;

a barrier layer deposited over the patterned insulating layer including overlying the field and inside surfaces of the at least one opening, the barrier layer comprising a refractory metal or an alloy comprising a refractory metal;

a first copper seed layer, formed by chemical vapor deposition, disposed over the barrier layer, the first copper seed layer substantially continuously covering inside surfaces of the at least one opening;

a second copper seed layer, formed by physical vapor deposition, disposed over the first copper seed layer, said second seed layer being thicker than said first seed layer over the field; and

electroplated copper over the second seed layer.

53. A multiple seed layer structure used to fabricate copper interconnects, said multiple seed layer structure comprising:

a patterned insulating layer formed over a substrate, the patterned insulating layer including at least one opening and a field surrounding the at least one opening;

a barrier layer formed over the patterned insulating layer including overlying the field and inside surfaces of the at least one opening, the barrier layer comprising a refractory metal or an alloy comprising a refractory metal;

a first copper seed layer, formed by physical vapor deposition, disposed over the barrier layer;

a second copper seed layer, formed by chemical vapor deposition, disposed over the first copper seed layer, the second copper seed layer substantially continuously covering inside surfaces of the at least one opening, said first seed layer being thicker than said second seed layer over the field; and

electroplated copper over the second seed layer.

54. A multiple seed layer structure used to fabricate metallic interconnects, said multiple seed layer structure comprising:

a patterned insulating layer formed on a substrate, the patterned insulating layer including at least one opening and a field surrounding the at least one opening;

a barrier layer formed over the field and inside surfaces of the at least one opening;

two or more seed layers deposited over the barrier layer using two or more different deposition techniques; and

an electroplated metallic layer formed over the two or more seed layers, the electroplated metallic layer comprising a material selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.

55. A metallic filled via or trench interconnect fabricated by using a multiple seed layer structure, said multiple seed layer structure comprising:

a patterned insulating layer formed on a substrate, the patterned insulating layer including at least one opening and a field surrounding the at least one opening;

a barrier layer disposed over the patterned insulating layer, including inside surfaces of the at least one opening;

a substantially conformal seed layer disposed over the barrier layer, including inside surfaces of the at least one opening, said substantially conformal seed layer comprises a material selected from the group consisting of Cu, Ag, or alloys comprising one or more of these metals;

a substantially non-conformal seed layer disposed over the substantially conformal seed layer, said substantially non-conformal seed layer comprises a material selected from the group consisting of Cu, Ag, or alloys comprising one or more of these metals, said substantially non-conformal seed layer being thicker than said substantially conformal seed layer over the field; and

an electroplated metallic layer deposited over the substantially non-conformal seed layer, said electroplated metallic layer comprising a material selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.

56. A metallic filled via or trench interconnect fabricated by using a multiple seed layer structure, said multiple seed layer structure comprising:

a patterned insulating layer formed on a substrate, the patterned insulating layer including at least one opening and a field surrounding the at least one opening;

a barrier layer disposed over the patterned insulating layer, including inside surfaces of the at least one opening;

a substantially non-conformal seed layer disposed over the barrier layer, said substantially non-conformal seed layer comprises a material selected from the group consisting of Cu, Ag, or alloys comprising one or more of these metals;

a substantially conformal seed layer disposed over the substantially non-conformal seed layer, said substantially conformal seed layer comprises a material selected from the group consisting of Cu, Ag, or alloys comprising one or more of these metals, said substantially non-conformal seed layer being thicker than said substantially conformal seed layer over the field; and

an electroplated metallic layer deposited over the substantially conformal seed layer, said electroplated metallic layer comprising a material selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.

57. A metallic interconnect, said metallic interconnect comprises:

a barrier layer disposed over an opening in an insulating layer including over inside bottom and sidewall surfaces of the opening;

a first seed layer disposed over the barrier layer, which first seed layer is formed by a first deposition technique;

a second seed layer disposed over the first seed layer, which second seed layer is formed by a second deposition technique, the first and second deposition techniques being different; and

an electroplated metallic layer disposed over the second seed layer, wherein the electroplated metallic layer comprises a material selected from a group consisting of Cu, Ag, or alloys comprising one or more of these metals.