Composition compatible with aluminum planarization and methods therefore

• US 6,720,265 B2
• Filed: 08/05/2002
• Issued: 04/13/2004
• Est. Priority Date: 08/31/1999
• Status: Expired due to Fees

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Chopra, Dinesh
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): ROCCHEGIANI, RENZO
• Application Number:
  US10/212,329
• Publication Number:
  US 20020192942A1
• Time in Patent Office: 617 Days
• Field of Search: 438/689, 438/692, 438/691, 438/693, 438/699
• US Class Current: 438/692
• CPC Class Codes: C09G 1/04 Aqueous dispersions C09G1/02 takes precedence
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]

Abstract

A planarization method includes providing an aluminum-containing surface and positioning it for contact with a fixed abrasive article in the presence of a composition preferably including a surfactant, a complexant, and an oxidant, wherein the solution has a pH of less than about 10.

Claims

1. A planarization method comprising:

providing a wafer comprising an aluminum-containing surface;

positioning the aluminum-containing surface to interface with a fixed abrasive article;

supplying a planarization composition suitable for use with the aluminum-containing surface in proximity to the interface; and

planarizing the surface using the fixed abrasive article and the planarization composition, the planarization composition comprising a surfactant, a complexant, and an oxidant, wherein the planarization composition has a pH less than about 10.

2. The method according to claim 1 wherein the surface of the wafer comprises aluminum in a molar amount of about 50% or more.

3. The method according to claim 1, wherein the planarization composition has a pH less than about 7.0.

4. The method according to claim 1, wherein the planarization composition has a pH of about 6.0 to about 8.0.

5. The method according to claim 1, wherein the oxidant is present in the planarization composition in an amount of about 0.5% to about 15% by volume.

6. The method according to claim 5, wherein the oxidant is selected from the group consisting of Fe(NO₃)₂, KMnO₄, H₂O₂, KNO₃, HNO₃, KIO₃, ammonium persulfate, ammonium molybdate, and a combination thereof.

7. The method according to claim 1, wherein the surfactant is present in the planarization composition in an amount 1% to about 10% by volume.

8. The method according to claim 7, wherein the surfactant is selected from the group consisting of polyethylene glycol, polyoxyethylene ether, glycerol, polypropylene glycol, and a combination thereof.

9. The method according to claim 1, wherein the complexant is present in the planarization composition in an amount of about 1% to about 10% by weight.

10. The method according to claim 9, wherein the complexant is selected from the group consisting of triethanolamine, ethylenediamine, ammonium citrate, ammonium phosphate, ammonium oxalate, ammonium carbonate, and a combination thereof.

11. The method according to claim 1, wherein the aluminum-containing surface comprises elemental aluminum.

12. The method according to claim 1, wherein the surface comprises an aluminum alloy.

13. The method according to claim 1, wherein the planarization composition further comprises a thickener in an amount sufficient to achieve a viscosity of the planarization composition of about 10 centipoise to about 20 centipoise at ambient temperature.

14. The method according to claim 1, wherein the planarization composition further comprises a buffering agent selected from the group consisting of potassium hydrogen phthalate, ammonium citrate, ammonium phosphate, and a combination thereof.

15. The method according to claim 1, wherein the planarization composition further comprises an aluminum corrosion inhibitor comprising from about 0.01% to about 2% by weight.

16. The method according to claim 15, wherein the aluminum corrosion inhibitor is selected from the group consisting of a phosphate, a polyphosphate, a silicate, and combination thereof.

17. The method according to claim 1, wherein the fixed abrasive article comprises a plurality of abrasive particles, wherein a majority of the plurality of abrasive particles comprise SiO₂.

18. The method according to claim 1, wherein the fixed abrasive article comprises a majority of SiO₂ abrasive particles and the planarization composition has a pH less than about 8.

19. The method according to claim 1, wherein the fixed abrasive article comprises an elongated fixed abrasive capable of planarizing the surface of a first wafer with a first portion of the elongated fixed abrasive and surface of a second wafer with a second portion of the elongated fixed abrasive.

20. A planarization method for use in forming an interconnect:

providing a wafer having a patterned dielectric layer formed thereon and an aluminum-containing layer formed over the patterned dielectric layer;

positioning a first portion of a fixed abrasive for contact with the aluminum-containing layer;

providing a planarization composition for use with the aluminum-containing layer in proximity to the contact between the fixed abrasive and the aluminum-containing layer, wherein the planarization composition comprises a surfactant, a complexant, and about 0.5% to about 15% by volume of an oxidant, wherein the planarization composition has a pH less than about 10; and

planarizing the aluminum-containing layer using the fixed abrasive and the planarization composition.

21. The method according to claim 20, wherein the aluminum-containing layer of the wafer comprises aluminum in a molar amount of about 50% or more.

22. The method according to claim 20, wherein the planarization composition has a pH less than about 7.0.

23. The method according to claim 20, wherein the planarization composition has a pH of about 6.0 to about 8.0.

24. The method according to claim 20, wherein the oxidant is selected from the group consisting of Fe(NO₃)₂, KMnO₄, H₂O₂, KNO₃, HNO₃, KIO₃, ammonium persulfate, ammonium molybdate, and a combination thereof.

25. The method according to claim 20, wherein the surfactant present in the planarization composition in an amount 1% to about 10% by volume.

26. The method according to claim 25, wherein the surfactant is selected from the group consisting of polyethylene glycol, polyoxyethylene ether, glycerol, polypropylene glycol, and a combination thereof.

27. The method according to claim 20, wherein the complexant is present in the planarization composition in an amount of about 1% to about 10% by weight.

28. The method according to claim 27, wherein the complexant is selected from the group consisting of triethanolamine, ethylenediamine, ammonium citrate, ammonium phosphate, ammonium oxalate, ammonium carbonate, and a combination thereof.

29. The method according to claim 20, wherein the aluminum-containing layer comprises elemental aluminum.

30. The method according to claim 20, wherein the aluminum-containing layer comprises an aluminum alloy.

31. The method according to claim 20, wherein the planarization composition further comprises a thickener in an amount sufficient to achieve a viscosity of the planarization composition of about 10 centipoise to about 20 centipoise at ambient temperature.

32. The method according to claim 20, wherein the planarization composition further comprises a buffering agent selected from the group consisting of hydrogen phthalate, ammonium citrate, ammonium phosphate, and a combination thereof.

33. The method according to claim 20, wherein the planarization composition further comprises an aluminum corrosion inhibitor selected from the group consisting of a phosphate, a polyphosphate, a silicate, and combination thereof.

34. The method according to claim 20, wherein the fixed abrasive comprises a plurality of abrasive particles, wherein a majority of the plurality of abrasive particles comprise SiO₂.

35. The method according to claim 20, wherein the fixed abrasive comprises a majority of SiO₂ abrasive particles and the planarization composition has a pH less than about 8.0.

36. The method according to claim 20, wherein planarizing is accomplished at a about 24°

C. or less.

37. The method according to claim 20, wherein the fixed abrasive comprises an elongated fixed abrasive capable of planarizing the aluminum-containing layer on a first wafer with the first portion on the elongated fixed abrasive and an aluminum-containing layer on a second wafer with a second portion on the elongated fixed abrasive.

38. A planarization method comprising:

providing a substrate assembly comprising at least one aluminum-containing surface region;

providing a fixed abrasive;

providing a planarization composition at an interface between the at least one surface region and the fixed abrasive suitable for use with the at least one surface region, wherein the planarization composition comprises a surfactant, a complexant, and an oxidant, wherein the planarization composition has a pH less than about 10; and

planarizing the at least one surface region using the fixed abrasive and the planarization composition.

39. The method according to claim 38, wherein the at least one surface region comprises aluminum in a molar amount of about 50% or more.

40. The method according to claim 38, wherein the planarization composition has a pH less than about 7.0.

41. The method according to claim 38, wherein the planarization composition has a pH of about 6.0 to about 8.0.

42. The method according to claim 38, wherein the oxidant is present in the planarization composition in an amount of about 0.5% to about 15% by volume.

43. The method according to claim 42, wherein the oxidant is selected from the group consisting of Fe(NO₃)₂, KMnO₄, H₂O₂, KNO₃, HNO₃, KIO₃, ammonium persulfate, ammonium molybdate, and a combination thereof.

44. The method according to claim 38, wherein the surfactant is present in the planarization composition in an amount 1% to about 10% by volume.

45. The method according to claim 44, wherein the surfactant is selected from then group consisting of polyethylene glycol, polyoxyethylene ether, glycerol, polypropylene glycol, and a combination thereof.

46. The method according to claim 38, wherein the complexant is present in the planarization composition in an amount of about 1% to about 10% by weight.

47. The method according to claim 46, wherein the complexant is selected from the group consisting of triethanolamine, ethylenediamine, ammonium citrate, ammonium phosphate, ammonium oxalate, ammonium carbonate, and a combination thereof.

48. The method according to claim 38, wherein the at least one surface region comprises elemental aluminium.

49. The method according to claim 38, wherein the at least one surface region comprises an aluminum alloy.

50. The method according to claim 38, wherein the planarization composition further comprises a thickener in an amount sufficient to achieve a viscosity of the planarization composition of about 10 centipoise to about 20 centipoise at ambient temperature.

51. The method according to claim 38, wherein the planarization composition further comprises a buffering agent selected from the group consisting of potassium hydrogen phthalate, ammonium citrate, ammonium phosphate, and a combination thereof.

52. The method according to claim 38, wherein the planarization composition further comprises an aluminum corrosion inhibitor selected from the group consisting of a phosphate, a polyphosphate, a silicate, and combination thereof.

53. The method according to claim 38, wherein the fixed abrasive comprises a plurality of abrasive particles, wherein a majority of the plurality of abrasive particles comprise SiO₂.

54. The method according to claim 38, wherein the fixed abrasive comprises a majority of SiO₂ abrasive particles and the planarizing composition has a pH less than about 8.0.

55. The method according to claim 38, wherein planarizing is accomplished at a temperature of about 24°

C. or less.

56. The method according to claim 38, wherein the fixed abrasive comprises an elongated fixed abrasive capable of planarizing the at least one aluminum-containing surface region of a first substrate assembly with a first portion of the elongated fixed abrasive and a second aluminum-containing surface region of a second substrate assembly with a second portion of the elongated fixed abrasive.

57. The method according to claim 56, wherein the planarization composition comprises at least one of an optional agent selected from the group consisting of a buffering agent;

a thickener; and

an aluminum corrosion inhibitor.

58. A planarization method comprising:

providing a wafer comprising an aluminum-containing surface;

locating the surface of the wafer to interface with a fixed abrasive article;

providing a planarization composition suitable for use with the surface in proximity to the interface; and

planarizing the surface using the fixed abrasive article and the planarization composition, wherein planarizing the surface comprises planarizing the surface at a temperature of about 24°

C. or less, wherein the planarization composition comprises a surfactant, a complexant, and an oxidant, and further wherein the planarization composition has a pH less than about 10.

59. The method according to claim 58, wherein the surface of the wafer comprises aluminum in a molar amount of about 50% or more.

60. The method according to claim 58, wherein the planarization composition as a pH of about 6.0 to about 8.0.

61. The method according to claim 58, wherein the oxidant is present in the planarization of about 0.5% to about 15% by volume.

62. The method according to claim 58, wherein the surfactant is present in the planarization composition in an amount 1% to about 10% by volume.

63. The method according to claim 58, wherein the complexant is present in the planarization composition in an amount of about 1% to about 10% by weight.

64. The method according to claim 58, wherein the surface comprises elemental aluminum.

65. The method according to claim 58, wherein the surface comprises an aluminum alloy.

66. The method according to claim 58, wherein the planarization composition further comprises a thickener in an amount sufficient to achieve a viscosity of the composition of about 10 centipoise to about 20 centipoise at ambient temperature.

67. The method according to claim 58, wherein the fixed abrasive article comprises a plurality of abrasive particles, wherein a majority of the plurality of abrasive particles comprise SiO₂.

68. The method according to claim 58, wherein the fixed abrasive article comprises a majority of SiO₂ abrasive particles and the planarization composition has a pH less than about 8.

69. The method according to claim 58, wherein the fixed abrasive article comprises an elongated fixed abrasive capable of planarizing the aluminum-containing surface of a first wafer with a first portion of the elongated fixed abrasive and aluminum-containing surface comprising aluminum of a second wafer with a second portion of the elongated fixed abrasive.