CMP slurry for planarizing metals

• US 6,520,840 B1
• Filed: 10/19/2000
• Issued: 02/18/2003
• Est. Priority Date: 10/27/1999
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Redeker, Fred C., Wang, Yuchun, Bajaj, Rajeev
• Primary Examiner(s): Rachuba, M.
• Assistant Examiner(s): MCDONALD, SHANTESE L
• Application Number:
  US09/692,723
• Time in Patent Office: 852 Days
• Field of Search: 451/60, 451/41, 451/446, 513/09, 106/3, 438/692, 438/693, 252/79.2
• US Class Current: 451/41
• CPC Class Codes: C09G 1/02 containing abrasives or grinding agents abrasives as such C09K3/14; polishing of semi-conductors H01L
• CPC Class Codes: C09K 3/1463 Aqueous liquid suspensions

Abstract

A CMP slurry is formulated with an oxidizer capable of oxidizing a metal undergoing planarization and yielding a complexing agent which complexes with the oxidized metal thereby minimizing overetching. The slurry may further include abrasive particles, inhibitors, pH adjusting agents, and combinations thereof.

Claims

1. A slurry for chemical mechanical polishing a metal, the slurry consisting essentially of:

a reagent having;

a first moiety for oxidizing the metal and for complexing with the metal or an oxidized metal, the first moiety comprising a peroxide group selected from the group of a peroxycarboxylic acid group, a peroxycarboxylate group, or combinations thereof, the first moiety producing a complexing agent comprising a carboxylic acid or a carboxylate following an oxidation reaction;

a second moiety for minimizing overetching the metal, wherein the second moiety comprises an alky group, an alkyl group derivative, an aryl group, an aryl group derivative, or combinations thereof;

an inhibitor;

abrasive particles;

base in an amount sufficient to provide a pH of about neutral; and

water.

2. The slurry according to claim 1, wherein the first moiety is a hydrophilic moiety and the second moiety is a hydrophobic moiety.

3. The slurry according to claim 1, wherein the metal is copper or a copper alloy.

4. The slurry according to claim 1, wherein the second moiety comprises benzene or a derivative thereof.

5. The slurry according to claim 1, wherein the base comprises sodium hydroxide or potassium hydroxide.

6. The slurry according to claim 1, comprising about 0.005 wt. % to about 25 wt. % of the reagent.

7. The slurry according to claim 1, wherein the inhibitor is benzotriazole in an amount of about 0.005 wt. % to about 0.5 wt. %.

8. The slurry according to claim 7, comprising about 0.5 to about 5 wt. % of the reagent and about 0.001 to about 0.1 wt. % of benzotriazole.

9. The slurry according to claim 1, wherein the slurry consists essentially of between about 0.01 wt. % and about 0.1 wt. % of peracetic acid, the slurry further comprising between about 0.05 wt. % and about 0.3 wt. % of benzotriazole, between about 5 wt. % and about 20 wt. % abrasives, and potassium hydroxide in a sufficient amount to provide a pH between about 7 and about 8.

10. A slurry for chemical mechanical polishing a metal, the slurry comprising a reagent having:

a first moiety for oxidizing the metal and for complexing with the metal and/or oxidized metal;

and

a second moiety for minimizing overetching the metal, wherein the second moiety comprises a polyethylene glycol.

11. The slurry according to claim 10, wherein the first moiety is reduced to a complexing agent for the metal or oxidized metal.

12. The slurry according to claim 11, wherein the first moiety comprises a peroxide group.

13. The slurry according to claim 12, wherein the peroxide group comprises a peroxycarboxylic acid group or a peroxycarboxylate group and the resulting complexing agent comprises a carboxylic acid or a carboxylate.

14. The slurry according to claim 10, wherein the polyethylene glycol comprises about 15 repeating monomer units.

15. The slurry according to claim 14, wherein the first moiety comprises at least one peroxycarboxylic acid or peroxycarboxylate group.

16. The slurry according to claim 10, further comprising a base.

17. The slurry according to claim 16, wherein the base and the reagent have a molar ratio of the base to the reagent between about 1:

1 and about 1;

2.

18. The slurry according to claim 16, wherein the base provides a pH of about neutral.

19. The slurry of claim 16, wherein the base comprises sodium hydroxide or potassium hydroxide.

20. The slurry according to claim 10, further comprising an inhibitor.

21. The slurry of claim 20, wherein the inhibitor is benzotriazole in an amount of about 0.005 wt. % to about 0.5 wt. %.

22. The slurry of claim 21, comprising about 0.5 to about 5 wt. % of the reagent and about 0.001 to about 0.1 wt. % of benzotiazole.

23. The slurry of claim 16, wherein the base and the reagent have a molar ratio of the base to the reagent between about 1:

1 and about 1;

2.

24. The slurry of claim 16, wherein the base provides a pH of about neutral.

25. The slurry according to claim 10, further comprising abrasive particles.

26. The slurry of claim 10, wherein the metal is copper or a copper alloy and the second moiety comprises an ark group or a derivative thereof.

27. The slurry of claim 10, wherein the composition comprises between about 0.005 wt. % to about 25 wt. % of the reagent.

28. A method of planarizing a surface of a metal layer, the method comprising:

polishing the surface with a slurry consisting essentially of;

a reagent having;

a first moiety for oxidizing the metal and for complexing with the metal or an oxidized metal, the first moiety comprising a peroxide group selected from the group of a peroxycarboxylic acid group, a peroxycarboxylate group, or combinations thereof, the first moiety producing a complexing agent comprising carboxylic acid or a carboxylate following an oxidation reaction; and

a

a second moiety for minimizing overetching of the metal, wherein the second moiety comprises an alkyl group, an alkyl group derivative, an aryl group, an aryl group derivative, or combinations thereof;

an inhibitor,

abrasive particles;

base in an amount sufficient to provide a pH between about 7 and about 8; and

water.

29. The method according to claim 28, wherein the metal is copper or a copper alloy.

30. The method according to claim 29, wherein the second moiety comprises benzene or a derivative thereof.

31. The method according to claim 28, wherein the base is sodium hydroxide or potassium hydroxide.

32. The method according to claim 28, wherein the reagent is present in an amount of about 0.005 wt. % to about 25 wt. %.

33. The method according to claim 28, wherein the inhibitor is benzotriazole and is present in an amount of about 0.005 wt. %. to about 0.5 wt. %.

34. The method according to claim 33, wherein the slurry contains about 0.5 to about 5 wt. % of the reagent and about 0.001 to about 0.1 wt. % of the inhibitor.

35. The method according to claim 28, wherein the slurry further comprises up to about 30 wt. % of abrasive particles.

36. The method according to claim 28, wherein the slurry consists essentially of between about 0.01 wt. % and about 0.1 wt. % of peracetic acid, the slurry further comprising between about 0.05 wt. % and about 0.3 wt. % of benzotriazole, between about 5 wt. % and about 20 wt. % abrasives, and potassium hydroxide in a sufficient amount to provide a pH between about 7 and about 8.

48. The method of claim 29, wherein the reagent is present in an amount of about 0.005 wt. % to about 25 wt. %.

49. The method of claim 29, wherein the inhibitor is benzotriazole and is present in an amount of about 0.005 wt. % to about 0.5 wt. %.

50. The method of claim 49, wherein the slurry contains about 0.5 to about 5 wt. % of the reagent and about 0.001 to about 0.1 wt. % of the inhibitor.

37. A method for chemical mechanical polishing a metal, the method comprising polishing the surface with a slurry comprising:

a reagent having;

a first moiety for oxidizing the metal and for complexing with the metal and/or oxidized metal; and

a second moiety for minimizing overetching the metal, wherein the second moiety comprises a polyethylene glycol.

38. The method according to claim 37, herein the first moiety is reduced to a complexing agent for the metal or oxidized metal.

39. The method according to claim 38, wherein the first moiety comprises a peroxide group.

40. The method according to claim 39, wherein the peroxide group comprises a peroxycarboxylic acid group or a peroxycarboxylate group and the resulting complexing agent comprises a carboxylic acid or a carboxylate.

41. The method according to claim 37, wherein the polyethylene glycol comprises about 15 repeating units.

42. The method according to claim 41, wherein the first moiety comprises at least one peroxycarboxylic acid or peroxycarboxylate group.

43. The method according to claim 37, wherein the metal is copper or a copper alloy.

44. The method according to claim 37, wherein the slurry further comprises a base.

45. The method according to claim 44, wherein the base and the reagent have a molar ratio of the base to the reagent between about 1:

1 and about 1;

2.

46. The method according to claim 44, wherein the base provides a pH of about neutral.

47. The method according to claim 37, wherein the reagent further contains an inhibitor.

51. The method of claim 37, wherein the slurry further comprises up to about 30 wt. % of abrasive particles.

52. The method of claim 37, wherein the base and the reagent have a molar ratio of the base to the reagent between about 1:

1 and about 1;

2.

53. The method of claim 37, wherein the base provides a pH of about neutral.

54. A slurry for chemical mechanically polishing a metal, the slurry consisting essentially of:

between about 0.01 wt. % and about 0.1 wt. % of peracetic acid;

between about 5 wt. % and about 20 wt. % abrasives;

between about 0.05 wt. % and about 0.3 wt. % of benzotriazole;

potassium hydroxide in a sufficient amount to provide a pH between about 7 and, about 8; and

water.

55. A method of planarizing a surface of a metal layer, the method comprising chemical mechanical polishing the surface with a slurry consisting essentially of:

between about 0.01 wt. % and about 0.1 wt. % of peracetic acid;

between about 5 wt. % and about 20 wt. % abrasives;

between about 0.05 wt. % and about 0.3 wt. % of benzotriazole;

potassium hydroxide in a sufficient amount to provide a pH between about 7 and about 8; and

water.