Composition compatible with aluminum planarization and methods therefore

• US 20020192942A1
• Filed: 08/05/2002
• Published: 12/19/2002
• Est. Priority Date: 08/31/1999
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Dinesh, Chopra
• Granted Patent: US 6,720,265 B2
• Time in Patent Office: Days
• US Class Current: 438/633
• 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:

positioning an aluminum-containing surface of a wafer surface to interface with a fixed abrasive article;

supplying an aluminum CMP composition in proximity to the interface; and

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

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

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

4. The method according to claim 1, wherein the 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 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 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 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 aluminum-containing surface comprises an aluminum alloy.

13. The method according to claim 1, wherein the 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.

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

16. The method of 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 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 comprises a majority of SiO₂ abrasive particles and the aluminum CMP composition has a pH less than about 8.

19. The method according lo claim 1, wherein planarizing is accomplished at a temperature of about 24°

C. or less.

20. The method according to claim 1, wherein the fixed abrasive comprises an elongated fixed abrasive capable of planarizing the aluminum-containing surface on a first wafer with a first portion on the elongated fixed abrasive and an aluminum-containing surface on a second wafer with a second portion on the elongated fixed abrasive.

21. 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 composition in proximity to the contact between the fixed abrasive and the metal layer, wherein the composition comprises a surfactant, a complexant, and about 0.5% to about 15% by volume of an oxidant, wherein the composition has a pH less than about 10; and

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

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

23. The method according to claim 21, wherein the composition has a pH less than about 7.0.

24. The method according to claim 21, wherein the composition has a pH of about 6.0 about 8.0.

25. The method according to claim 21, wherein the oxidant is present in the composition in an amount of about 0.5% to about 10% by volume.

26. The method according to claim 25, 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.

27. The method according to claim 21, wherein the surfactant is present in the composition in an amount 1% to about 10% by volume.

28. The method according to claim 27, wherein the surfactant is selected from the group consisting of polyethylene glycol, polyoxyethylene ether, glycerol, polypropylene glycol, and a combination thereof.

29. The method according to claim 21, wherein the complexant is present in the composition in an amount of about 1% to about 10% by weight.

30. The method according to claim 29, wherein the complexant is selected from the group consisting of triethanolamine, ethylenediamine, ammonium citrate, ammonium phosphate, ammonium oxalate, ammonium carbonate, and a combination thereof.

31. The method according to claim 21, wherein the aluminum-containing surface comprises elemental aluminum.

32. The method according to claim 21, wherein the aluminum-containing surface comprises an aluminum alloy.

33. The method according to claim 21, wherein the 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.

34. The method according to claim 21, wherein the composition further comprises a buffering agent selected from the group consisting of hydrogen phthalate, ammonium citrate, ammonium phosphate, and a combination thereof.

35. The method of according to claim 21, wherein the composition further comprises an aluminum corrosion inhibitor selected from the group consisting of a phosphate, a polyphosphate, a silicate, and combination thereof.

36. The method according to claim 21, wherein the fixed abrasive comprises a plurality of abrasive particles, wherein a majority of the plurality of abrasive particles comprise SiO₂.

37. The method according to claim 21, wherein the fixed abrasive comprises a majority of SiO₂ abrasive particles and the aluminum CMP composition has a pH less than about 8.0.

38. The method according to claim 21, wherein planarizing is accomplished at a temperature of about 24°

C. or less.

39. The method according to claim 21, wherein the fixed abrasive comprises an elongated fixed abrasive capable of planarizing the aluminum-containing surface on a first wafer with the first portion on the elongated fixed abrasive and an aluminum-containing surface on a second wafer with a second portion on the elongated fixed abrasive.

40. A planarization method comprising:

providing a substrate assembly including at least one region of a aluminum-containing metal;

providing a fixed abrasive;

providing a composition at an interface between the at least one region of aluminum-containing metal and the fixed abrasive, wherein the composition comprises a surfactant, a complexant, and an oxidant, wherein the composition has a pH less than about 10; and

planarizing the at least one region of aluminum-containing metal using the fixed abrasive and the composition.

41. The method according to claim 40, wherein the at least one region of aluminum-containing metal comprises aluminum in a molar amount of about 50% or more.

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

43. The method according to claim 40, wherein the composition has a pH of about 6.0 to about 8.0.

44. The method according to claim 40, wherein the oxidant is present in the composition in an amount of about 0.5% to about 15% by volume.

45. The method according to claim 44, 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.

46. The method according to claim 40, wherein the surfactant is present in the composition in an amount 1% to about 10% by volume.

47. The method according to claim 46, wherein the surfactant is selected from then group consisting of polyethylene glycol, polyoxyethylene ether, glycerol, polypropylene glycol, and a combination thereof.

48. The method according to claim 40, wherein the complexant is present in the composition in an amount of about 1% to about 10% by weight.

49. The method according to claim 48, wherein the complexant is selected from the group consisting of triethanolamine, ethylenediamine, ammonium citrate, ammonium phosphate, ammonium oxalate, ammonium carbonate, and a combination thereof.

50. The method according to claim 40, wherein the aluminum-containing surface comprises elemental aluminum.

51. The method according to claim 40, wherein the aluminum-containing surface comprises an aluminum alloy.

52. The method according to claim 40, wherein the 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.

53. The method according to claim 40, wherein the composition further comprises a buffering agent selected from the group consisting of potassium hydrogen phthalate, ammonium citrate, ammonium phosphate, and a combination thereof.

54. The method of according to claim 40, wherein the composition further comprises an aluminum corrosion inhibitor selected from the group consisting of a phosphate, a polyphosphate, a silicate, and combination thereof.

55. The method according to claim 40, wherein the fixed abrasive comprises a plurality of abrasive particles, wherein a majority of the plurality of abrasive particles comprise SiO₂.

56. The method according to claim 40, wherein the fixed abrasive comprises a majority of SiO₂ abrasive particles and the aluminum CMP composition has a pH less than about 8.0.

57. The method according to claim 40, wherein planarizing is accomplished at a temperature of about 24°

C. or less.

58. The method according to claim 40, wherein the fixed abrasive comprises an elongated fixed abrasive capable of planarizing the at least one region of an aluminum-containing metal on a first substrate assembly with a first portion on the elongated fixed abrasive and a second region of an aluminum-containing metal on a second substrate assembly with a second portion on the elongated fixed abrasive.

60. The composition according to claim 58, further comprising at least one of an optional agent selected from the group consisting of a buffering agent;

a thickener; and

an aluminum corrosion inhibitor.

59. A composition consisting essentially of a surfactant in an amount of about 1% to about 10% by volume;

a complexant in an amount of about 1% to about 10% by volume; and

an oxidant in an amount of about 0.5% to about 15% by volume, wherein the composition has a pH of about 1 to about 10 and is effective to planarize an aluminum-containing surface in the presence of a fixed abrasive.

61. A planarization method comprising:

positioning an aluminum-containing surface of a wafer surface to interface with a fixed abrasive article;

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

planarizing the wafer 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.

62. The method according to claim 61 wherein the aluminum-containing surface of the wafer comprises aluminum in a molar amount of about 50% or more.

63. The method according to claim 61, wherein the planarization composition has a pH less than about 7.0.

64. The method according to claim 61, wherein the planarization composition has a pH of about 6.0 to about 8.0.

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

66. The method according to claim 65, 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.

67. The method according to claim 61, wherein the surfactant is present in the planarization composition in an amount 1% to about 10% by volume.

68. The method according to claim 67, wherein the surfactant is selected from the group consisting of polyethylene glycol, polyoxyethylene ether, glycerol, polypropylene glycol, and a combination thereof.

69. The method according to claim 61, wherein the complexant is present in the planarization composition in an amount of about 1% to about 10% by weight.

70. The method according to claim 69, wherein the complexant is selected from the group consisting of triethanolamine, ethylenediamine, ammonium citrate, ammonium phosphate, ammonium oxalate, ammonium carbonate, and a combination thereof.

71. The method according to claim 61, wherein the aluminum-containing surface comprises elemental aluminum.

72. The method according to claim 61, wherein the aluminum-containing surface comprises an aluminum alloy.

73. The method according to claim 61, 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.

74. The method according to claim 61, 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.

75. The method according to claim 61, wherein the planarization composition further comprises an aluminum corrosion inhibitor comprising from about 0.01% to about 2% by weight.

76. The method according to claim 75, wherein the aluminum corrosion inhibitor is selected from the group consisting of a phosphate, a polyphosphate, a silicate, and combination thereof.

77. The method according to claim 61, wherein the fixed abrasive article comprises a plurality of abrasive particles, wherein a majority of the plurality of abrasive particles comprise SiO₂.

78. The method according to claim 61, wherein the fixed abrasive article comprises a majority of SiO₂ abrasive particles and the planarization composition has a pH less than about 8.

79. The method according to claim 61, wherein the fixed abrasive article comprises an elongated fixed abrasive capable of planarizing the aluminum-containing surface on a first wafer with a first portion on the elongated fixed abrasive and an aluminum-containing surface on a second wafer with a second portion on the elongated fixed abrasive.

80. 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 metal layer, wherein the planarization composition comprises a surfactant, a complexant, and about 0.5% to about 10% 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.

81. The method according to claim 80, wherein the aluminum-containing surface of the wafer comprises aluminum in a molar amount of about 50% or more.

82. The method according to claim 80, wherein the planarization composition has a pH less than about 7.0.

83. The method according to claim 80, wherein the planarization composition has a pH of about 6.0 to about 8.0.

84. The method according to claim 80, wherein the oxidant is present in the planarization composition in an amount of about 0.5% to about 15% by volume.

85. The method according to claim 84, 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.

86. The method according to claim 80, wherein the surfactant is present in the planarization composition in an amount 1% to about 10% by volume.

87. The method according to claim 86, wherein the surfactant is selected from the group consisting of polyethylene glycol, polyoxyethylene ether, glycerol, polypropylene glycol, and a combination thereof.

88. The method according to claim 80, wherein the complexant is present in the planarization composition in an amount of about 1% to about 10% by weight.

89. The method according to claim 88, wherein the complexant is selected from the group consisting of triethanolamine, ethylenediamine, ammonium citrate, ammonium phosphate, ammonium oxalate, ammonium carbonate, and a combination thereof.

90. The method according to claim 80, wherein the aluminum-containing surface comprises elemental aluminum.

91. The method according to claim 80, wherein the aluminum-containing surface comprises an aluminum alloy.

92. The method according to claim 80, 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.

93. The method according to claim 80, 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.

94. The method according to claim 80, 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.

95. The method according to claim 80, wherein the fixed abrasive comprises a plurality of abrasive particles, wherein a majority of the plurality of abrasive particles comprise SiO₂.

96. The method according to claim 80, wherein the fixed abrasive comprises a majority of SiO₂ abrasive particles and the planarization composition has a pH less than about 8.0.

97. The method according to claim 80, wherein planarizing is accomplished at a temperature of about 24°

C. or less.

98. The method according to claim 80, wherein the fixed abrasive comprises an elongated fixed abrasive capable of planarizing the aluminum-containing surface on a first wafer with the first portion on the elongated fixed abrasive and an aluminum-containing surface on a second wafer with a second portion on the elongated fixed abrasive.

99. A planarization method comprising:

providing a substrate assembly including at least one region of a aluminum-containing metal;

providing a fixed abrasive;

providing a planarization composition for use with the aluminum-containing surface at an interface between the at least one region of aluminum-containing metal and the fixed abrasive, 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 region of aluminum-containing metal using the fixed abrasive and the planarization composition.

100. The method according to claim 99, wherein the at least one region of aluminum-containing metal comprises aluminum in a molar amount of about 50% or more.

101. The method according to claim 99, wherein the planarization composition has a pH less than about 7.0.

102. The method according to claim 99, wherein the planarization composition has a pH of about 6.0 to about 8.0.

103. The method according to claim 99, wherein the oxidant is present in the planarization composition in an amount of about 0.5% to about 15% by volume.

104. The method according to claim 103, 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.

105. The method according to claim 99, wherein the surfactant is present in the planarization composition in an amount 1% to about 10% by volume.

106. The method according to claim 105, wherein the surfactant is selected from then group consisting of polyethylene glycol, polyoxyethylene ether, glycerol, polypropylene glycol, and a combination thereof.

107. The method according to claim 99, wherein the complexant is present in the planarization composition in an amount of about 1% to about 10% by weight.

108. The method according to claim 107, wherein the complexant is selected from the group consisting of triethanolamine, ethylenediamine, ammonium citrate, ammonium phosphate, ammonium oxalate, ammonium carbonate, and a combination thereof.

109. The method according to claim 99, wherein the aluminum-containing surface comprises elemental aluminum.

110. The method according to claim 99, wherein the aluminum-containing surface comprises an aluminum alloy.

111. The method according to claim 99, 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.

112. The method according to claim 99, 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.

113. The method according to claim 99, 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.

114. The method according to claim 99, wherein the fixed abrasive comprises a plurality of abrasive particles, wherein a majority of the plurality of abrasive particles comprise SiO₂.

115. The method according to claim 99, wherein the fixed abrasive comprises a majority of SiO₂ abrasive particles and the planarizing composition has a pH less than about 8.0.

116. The method according to claim 99, wherein planarizing is accomplished at a temperature of about 24°

C. or less.

117. The method according to claim 99, wherein the fixed abrasive comprises an elongated fixed abrasive capable of planarizing the at least one region of an aluminum-containing metal on a first substrate assembly with a first portion on the elongated fixed abrasive and a second region of an aluminum-containing metal on a second substrate assembly with a second portion on the elongated fixed abrasive.

118. The method according to claim 117, 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.

120. The method according to claim 119, wherein the aluminum-containing surface of the wafer comprises aluminum in a molar amount of about 50% or more.

121. The method according to claim 119, wherein the planarization composition has a pH of about 6.0 to about 8.0.

122. The method according to claim 119, wherein the oxidant is present in the planarization composition in an amount of about 0.5% to about 15% by volume.

123. The method according to claim 119, wherein the surfactant is present in the planarization composition in an amount 1% to about 10% by volume.

124. The method according to claim 119, wherein the complexant is present in the planarization composition in an amount of about 1% to about 10% by weight.

125. The method according to claim 119, wherein the aluminum-containing surface comprises elemental aluminum.

126. The method according to claim 119, wherein the aluminum-containing surface comprises an aluminum alloy.

127. The method according to claim 119, 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.

128. The method according to claim 119, wherein the fixed abrasive article comprises a plurality of abrasive particles, wherein a majority of the plurality of abrasive particles comprise SiO₂.

129. The method according to claim 119, wherein the fixed abrasive article comprises a majority of SiO₂ abrasive particles and the planarization composition has a pH less than about 8.

130. The method according to claim 119, wherein the fixed abrasive article comprises an elongated fixed abrasive capable of planarizing the aluminum-containing surface on a first wafer with a first portion on the elongated fixed abrasive and an aluminum-containing surface on a second wafer with a second portion on the elongated fixed abrasive.

119. A planarization method comprising:

providing an aluminum-containing surface of a wafer surface to interface with a fixed abrasive article;

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

planarizing the wafer surface using the fixed abrasive article and the planarization composition, wherein planarizing the wafer surface comprises planarizing the wafer 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.