USRE45468EExpiredUtility

Barrier-slurry-free copper CMP process

Assignee: CHEN YI-CHENPriority: Jul 25, 2003Filed: Jul 27, 2006Granted: Apr 14, 2015

Est. expiryJul 25, 2023(expired)· nominal 20-yr term from priority

Inventors:Yi-Chen Chen Ching-Ming Tsai Ray-Ting Chang

H10P 52/403H10W 20/062B24D 13/14C09G 1/02

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Claims

Abstract

A method of polishing a metal layer comprising the following steps. A structure having an upper patterned dielectric layer with an opening therein is provided. A barrier layer is formed over the patterned upper dielectric layer and lining the opening. A metal layer is formed over the barrier layer, filling the opening. A first polish step employing a first slurry composition is conducted to remove a portion of the overlying metal layer. A second polish step employing the first slurry composition is conducted to: polish the partially removed overlying metal layer; and to expose portions of the barrier layer overlying the patterned upper dielectric layer. A third polish step employing a second slurry composition is conducted to remove the exposed barrier layer portions and exposing underlying portions of the patterned upper dielectric layer. A fourth polish step employing the second slurry composition and BTA is conducted to buff the exposed upper dielectric layer portions.

Claims

exact text as granted — not AI-modified

We claim:

1. A method of polishing a metal layer, comprising the steps of:
providing a structure having an upper patterned dielectric layer; the patterned dielectric layer having an opening formed therein;
forming a barrier layer over the patterned upper dielectric layer, the barrier layer lining the opening;
forming a metal layer over the barrier layer, filling the opening;
conducting a first polish step employing a first slurry composition, the first polish step removing a portion of the overlying metal layer;
conducting a second polish step employing the first slurry composition, the second polish step polishing the partially removed overlying metal layer and exposing portions of the barrier layer overlying the patterned upper dielectric layer;
conducting a third polish step employing a second slurry composition, the third polish step removing the exposed barrier layer portions and exposing underlying portions of the patterned upper dielectric layer; and
conducting a fourth polish step employing the second slurry composition and BTA, the fourth polish step buffing the exposed upper dielectric layer portions.

2. The method of claim 1 , wherein the first polish step is conducted on a first platen; the second and third polish steps are conducted on a second platen; and the fourth polish step is conducted on a third platen.

3. The method of claim 1 , wherein the first slurry composition is 600y-73 slurry manufactured by Cabot Microelectronics comprised of:
Al 2 O 3 : from about 0.4 to 0.6 wt. %;
H 2 O 2 : from about 2.6 to 3.4 wt. %;
KOH to adjust pH value; and
BTA as a corrosion behavior inhibitor.

4. The method of claim 1 , wherein the first slurry composition is 600y-73 slurry manufactured by Cabot Microelectronics comprised of:
Al 2 O 3 : about 0.5 wt. %;
H 2 O 2 : from about 2.8 to 3.2 wt. %;
KOH to adjust pH value; and
BTA as a corrosion behavior inhibitor.

5. The method of claim 1 , wherein the first slurry composition is 600y-73 slurry manufactured by Cabot Microelectronics having:
a) a pH of from about 2.8 to 4.3; and
b) a particulate size of from about 115 to 155 nm, weight basis.

6. The method of claim 1 , wherein the first slurry composition is 600y-73 slurry manufactured by Cabot Microelectronics having:
a) a pH of about 4.1; and
b) a particulate size of from about 120 to 150 nm, weight basis.

7. The method of claim 1 , wherein the second slurry composition is SS6 slurry manufactured by Cabot Microelectronics comprised of:
SiO 2 : from about 5.8 to 6.2 wt. %; and
KOH to adjust pH value.

8. The method of claim 1 , wherein the second slurry composition is SS6 slurry manufactured by Cabot Microelectronics comprised of:
SiO 2 : about 6.0 wt. %; and
KOH to adjust pH value.

9. The method of claim 1 , wherein the second slurry composition is SS6 slurry manufactured by Cabot Microelectronics having:
a) a pH of from about 9.8 to 11.4; and
b) a particulate size of from about 125 to 185 nm, weight basis.

10. The method of claim 1 , wherein the second slurry composition is SS6 slurry manufactured by Cabot Microelectronics having:
a) a pH of from about 10.0 to 11.2; and
b) a particulate size of from about 130 to 180 nm, weight basis.

11. The method of claim 1 , wherein the fourth polish step employs the second slurry composition that is SS6 slurry manufactured by Cabot Microelectronics comprised of:
SiO 2 : from about 5.8 to 6.2 wt. %; and
KOH to adjust pH value;

and from about 0.10 to 0.14% BTA.

12. The method of claim 1 , wherein the fourth polish step employs the second slurry composition that is SS6 slurry manufactured by Cabot Microelectronics comprised of:
SiO 2 : about 6.0 wt. %; and
KOH to adjust pH value;

and about 0.12% BTA.

13. The method of claim 1 , wherein the fourth polish step employs the second slurry composition that is SS6 slurry manufactured by Cabot Microelectronics having:
a) a pH of from about 9.8 to 11.4; and
b) a particulate size of from about 125 to 185 nm, weight basis;

and from about 0.10 to 0.14% BTA.

14. The method of claim 1 , wherein the fourth polish step employs the second slurry composition that is SS6 slurry manufactured by Cabot Microelectronics having:
a) a pH of from about 10.0 to 11.2; and
b) a particulate size of from about 130 to 180 nm, weight basis;

and about 0.12% BTA.

15. The method of claim 1 , wherein:
the first polish step is conducted at from about 2.0 to 2.4 psi for from about 36 to 44 seconds; and then at from about 1.0 to 1.4 psi for from about 18 to 22 seconds;
the second polish step is conducted at from about 1.0 to 1.4 psi for from about 41 to 49 seconds;
the third polish step is conducted at from about 1.8 to 2.2 psi for from about 31 to 39 seconds; and
the fourth polish step is conducted at from about 1.8 to 2.2 psi for from about 40 to 60 seconds.

16. The method of claim 1 , wherein:
the first polish step is conducted at about 2.2 psi for about 40 seconds; and then at about 1.2 psi for about 20 seconds;
the second polish step is conducted at about 1.2 psi for about 45 seconds;
the third polish step is conducted at about 2.0 psi for about 35 seconds; and
the fourth polish step is conducted at about 2.0 psi for about 50 seconds.

17. The method of claim 1 , wherein the structure is a semiconductor substrate.

18. The method of claim 1 , wherein the upper patterned dielectric layer is comprised of silicon oxide, silicon nitride, FSG or silicon oxynitride; the barrier layer is comprised of TaN or Ta; and the metal layer is comprised of copper aluminum or gold.

19. The method of claim 1 , wherein the upper patterned dielectric layer is comprised of silicon oxide; the barrier layer is comprised of TaN; and the metal layer is comprised of copper.

20. The method of claim 1 , wherein the patterned dielectric layer is from about 10,000 to 12,000 Å thick; and the barrier layer is from about 250 to 350 Åthick.

21. The method of claim 1 , wherein the patterned dielectric layer is about 11,100 Å thick; and the barrier layer is about 300 Å thick.

22. The method of claim 1 , wherein the partially removed overlying metal layer has a thickness of from about 6000 to 8000 Å.

23. The method of claim 1 , wherein the partially removed overlying metal layer has a thickness of about 7000 Å.

24. A method of polishing a metal layer, comprising the steps of:
providing a structure having an upper patterned dielectric layer; the patterned dielectric layer having an opening formed therein;
forming a barrier layer over the patterned upper dielectric layer, the barrier layer lining the opening;
forming a metal layer over the barrier layer, filling the opening;
conducting a first polish step on a first platen employing a first slurry composition, the first polish step removing a portion of the overlying metal layer;
conducting a second polish step on a second platen employing the first slurry composition, the second polish step polishing the partially removed overlying metal layer and exposing portions of the barrier layer overlying the patterned upper dielectric layer;
conducting a third polish step on the second platen employing a second slurry composition, the third polish step removing the exposed barrier layer portions and exposing underlying portions of the patterned upper dielectric layer; and
conducting a fourth polish step on a third platen employing the second slurry composition and BTA, the fourth polish step buffing the exposed upper dielectric layer portions.

25. The method of claim 24 , wherein the first slurry composition is 600y-73 slurry manufactured by Cabot Microelectronics comprised of:
Al 2 O 3 : from about 0.4 to 0.6 wt. %;
H 2 O 2 : from about 2.6 to 3.4 wt. %;
KOH to adjust pH value; and
BTA as a corrosion behavior inhibitor.

26. The method of claim 24 , wherein the first slurry composition is 600y-73 slurry manufactured by Cabot Microelectronics comprised of:
Al 2 O 3 : about 0.5 wt. %;
H 2 O 2 : from about 2.8 to 3.2 wt. %;
KOH to adjust pH value; and
BTA as a corrosion behavior inhibitor.

27. The method of claim 24 , wherein the first slurry composition is 600y-73 slurry manufactured by Cabot Microelectronics having:
a) a pH of from about 2.8 to 4.3; and
b) a particulate size of from about 115 to 155 nm, weight basis.

28. The method of claim 24 , wherein the first slurry composition is 600y-73 slurry manufactured by Cabot Microelectronics having:
a) a pH of about 4.1; and
b) a particulate size of from about 120 to 150 nm, weight basis.

29. The method of claim 24 , wherein the second slurry composition is SS6 slurry manufactured by Cabot Microelectronics comprised of:
SiO 2 : from about 5.8 to 6.2 wt. %; and
KOH to adjust pH value.

30. The method of claim 24 , wherein the second slurry composition is SS6 slurry manufactured by Cabot Microelectronics comprised of:
SiO 2 : about 6.0 wt. %; and
KOH to adjust pH value.

31. The method of claim 24 , wherein the second slurry composition is SS6 slurry manufactured by Cabot Microelectronics having:
a) a pH of from about 9.8 to 11.4; and
b) a particulate size of from about 125 to 185 nm, weight basis.

32. The method of claim 24 , wherein the second slurry composition is SS6 slurry manufactured by Cabot Microelectronics having:
a) a pH of from about 10.0 to 11.2; and
b) a particulate size of from about 130 to 180 nm, weight basis.

33. The method of claim 24 , wherein the fourth polish step employs the second slurry composition that is SS6 slurry manufactured by Cabot Microelectronics comprised of:
SiO 2 : from about 5.8 to 6.2 wt. %; and
KOH to adjust pH value;

and from about 0.10 to 0.14% BTA.

34. The method of claim 24 , wherein the fourth polish step employs the second slurry composition that is SS6 slurry manufactured by Cabot Microelectronics comprised of:
SiO 2 : about 6.0 wt. %; and
KOH to adjust pH value;

and about 0.12% BTA.

35. The method of claim 24 , wherein the fourth polish step employs the second slurry composition that is SS6 slurry manufactured by Cabot Microelectronics having:
a) a pH of from about 9.8 to 11.4; and
b) a particulate size of from about 125 to 185 nm, weight basis;

and from about 0.10 to 0.14% BTA.

36. The method of claim 24 , wherein the fourth polish step employs the second slurry composition that is SS6 slurry manufactured by Cabot Microelectronics having:
a) a pH of from about 10.0 to 11.2; and
b) a particulate size of from about 130 to 180 nm, weight basis;

and about 0.12% BTA.

37. The method of claim 24 , wherein:
the first polish step is conducted at from about 2.0 to 2.4 psi for from about 36 to 44 seconds; and then at from about 1.0 to 1.4 psi for from about 18 to 22 seconds;
the second polish step is conducted at from about 1.0 to 1.4 psi for from about 41 to 49 seconds;
the third polish step is conducted at from about 1.8 to 2.2 psi for from about 31 to 39 seconds; and
the fourth polish step is conducted at from about 1.8 to 2.2 psi for from about 40 to 60 seconds.

38. The method of claim 24 , wherein:
the first polish step is conducted at about 2.2 psi for about 40 seconds; and then at about 1.2 psi for about 20 seconds;
the second polish step is conducted at about 1.2 psi for about 45 seconds;
the third polish step is conducted at about 2.0 psi for about 35 seconds; and
the fourth polish step is conducted at about 2.0 psi for about 50 seconds.

39. The method of claim 24 , wherein the structure is a semiconductor substrate.

40. The method of claim 24 , wherein the upper patterned dielectric layer is comprised of silicon oxide, silicon nitride, FSG or silicon oxynitride; the barrier layer is comprised of TaN or Ta; and the metal layer is comprised of copper, aluminum or gold.

41. The method of claim 24 , wherein the upper patterned dielectric layer is comprised of silicon oxide; the barrier layer is comprised of TaN; and the metal layer 18 is comprised of copper.

42. The method of claim 24 , wherein the patterned dielectric layer is from about 10,000 to 12,000 Å thick; and the barrier layer is from about 250 to 350 Å thick.

43. The method of claim 24 , wherein the patterned dielectric layer is about 11,100 Å thick; and the barrier layer is about 300 Å thick.

44. The method of claim 24 , wherein the partially removed overlying metal layer has a thickness of from about 6000 to 8000 Å.

45. The method of claim 24 , wherein the partially removed overlying metal layer has a thickness of about 7000 Å.

46. A method of polishing a metal layer, comprising the steps of:
providing a structure having an upper patterned dielectric layer; the patterned dielectric layer having an opening formed therein; forming a barrier layer over the patterned upper dielectric layer, the barrier layer lining the opening; forming a metal layer over the barrier layer, filling the opening; conducting a first polish step employing a first slurry composition, the first polish step removing a portion of the overlying metal layer; wherein the first slurry composition is 600y-73 slurry manufactured by Cabot Microelectronics comprised of:
Al 2 O 3 : from about 0.4 to 0.6 wt. %;
H 2 O 2 : from about 2.6 to 3.4 wt. %;
KOH to adjust pH value; and
BTA as a corrosion behavior inhibitor
conducting a second polish step employing the first slurry composition, the second polish step polishing the partially removed overlying metal layer and exposing portions of the barrier layer overlying the patterned upper dielectric layer; conducting a third polish step employing a second slurry composition, the third polish step removing the exposed barrier layer portions and exposing underlying portions of the patterned upper dielectric layer; wherein the second slurry composition is SS6 slurry manufactured by Cabot Microelectronics comprised of:
SiO 2 : from about 5.8 to 6.2 wt. %; and
KOH to adjust pH value; and
conducting a fourth polish step employing the second slurry composition and from about 0.10 to 0.14% BTA, the fourth polish step buffing the exposed upper dielectric layer portions.

47. The method of claim 46 , wherein the first polish step is conducted on a first platen; the second and third polish steps are conducted on a second platen; and the fourth polish step is conducted on a third platen.

48. The method of claim 46 , wherein the first slurry composition is comprised of:
Al 2 O 3 : about 0.5 wt. %; H 2 O 2 : from about 2.8 to 3.2 wt. %; KOH to adjust pH value; and BTA as a corrosion behavior inhibitor.

49. The method of claim 46 , wherein the first slurry composition has:
a) a pH of from about 2.8 to 4.3; and b) a particulate size of from about 115 to 155 nm, weight basis.

50. The method of claim 46 , wherein the first slurry composition has:
a) a pH of about 4.1; and b) a particulate size of from about 120 to 150 nm, weight basis.

51. The method of claim 46 , wherein the second slurry composition is comprised of:
SiO 2 : about 6.0 wt. %; and KOH to adjust pH value.

52. The method of claim 46 , wherein the second slurry composition has:
a) a pH of from about 9.8 to 11.4; and b) a particulate size of from about 125 to 185 nm, weight basis.

53. The method of claim 46 , wherein the second slurry composition has:
a) a pH of from about 10.0 to 11.2; and b) a particulate size of from about 130 to 180 nm, weight basis.

54. The method of claim 46 , wherein the fourth polish step employs the second slurry composition comprised of:
SiO 2 : about 6.0 wt. %; and KOH to adjust pH value;
and about 0.12% BTA.

55. The method of claim 46 , wherein the fourth polish step employs the second slurry composition that is SS6 slurry manufactured by Cabot Microelectronics having:
a) a pH of from about 9.8 to 11.4; and b) a particulate size of from about 125 to 185 nm, weight basis;
and from about 0.10 to 0.14% BTA.

56. The method of claim 46 , wherein the fourth polish step employs the second slurry composition that is SS6 slurry manufactured by Cabot Microelectronics having:
a) a pH of from about 10.0 to 11.2; and b) a particulate size of from about 130 to 180 nm, weight basis;
and about 0.12% BTA.

57. The method of claim 46 , wherein:
the first polish step is conducted at from about 2.0 to 2.4 psi for from about 36 to 44 seconds; and then at from about 1.0 to 1.4 psi for from about 18 to 22 seconds; the second polish step is conducted at from about 1.0 to 1.4 psi for from about 41 to 49 seconds; the third polish step is conducted at from about 1.8 to 2.2 psi for from about 31 to 39 seconds; and the fourth polish step is conducted at from about 1.8 to 2.2 psi for from about 40 to 60 seconds.

58. The method of claim 46 , wherein:
the first polish step is conducted at about 2.2 psi for about 40 seconds; and then at about 1.2 psi for about 20 seconds; the second polish step is conducted at about 1.2 psi for about 45 seconds; the third polish step is conducted at about 2.0 psi for about 35 seconds; and the fourth polish step is conducted at about 2.0 psi for about 50 seconds.

59. The method of claim 46 , wherein the structure is a semiconductor substrate.

60. The method of claim 46 , wherein the upper patterned dielectric layer is comprised of silicon oxide, silicon nitride, FSG or silicon oxynitride; the barrier layer is comprised of TaN or Ta; and the metal layer is comprised of copper aluminum or gold.

61. The method of claim 46 , wherein the upper patterned dielectric layer is comprised of silicon oxide; the barrier layer is comprised of TaN; and the metal layer 18 is comprised of copper.

62. The method of claim 46 , wherein the patterned dielectric layer is from about 10,000 to 12,000 Å thick; and the barrier layer is from about 250 to 350 Å thick.

63. The method of claim 46 , wherein the patterned dielectric layer is about 11,100 Å thick; and the barrier layer is about 300 Å thick.

64. The method of claim 46 , wherein the partially removed overlying metal layer has a thickness of from about 6000 to 8000 Å.

65. The method of claim 46 , wherein the partially removed overlying metal layer has a thickness of about 7000 Å.

66. A method of polishing a metal layer, comprising:
providing a structure having a patterned dielectric layer, the patterned dielectric layer having an opening formed therein; forming a barrier layer over the patterned dielectric layer, the barrier layer lining the opening; forming a metal layer over the barrier layer, the metal layer filling the opening; conducting a first polish step on a first platen employing a first slurry composition, the first polish step removing a portion of the overlying metal layer and leaving a remaining portion of the metal layer; conducting a second polish step on a second platen employing the first slurry composition, the second polish step removing the remaining portion of the metal layer and exposing portions of the barrier layer; conducting a third polish step on the second platen employing a second slurry composition, the third polish step removing the exposed barrier layer portions; and conducting a fourth polish step employing the second slurry composition, the fourth polish step buffing a portion of the patterned dielectric layer portions.

67. The method of claim 66, wherein the fourth polish step further comprises a corrosion inhibitor.

68. The method of claim 67, wherein the corrosion inhibitor comprises 1-H benzotriazole.

69. The method of claim 67, wherein the corrosion inhibitor comprises BTA.

70. The method of claim 66, wherein the fourth polish step is conducted on a third platen.

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