Use of corrosion inhibiting compounds to inhibit corrosion of metal plugs in chemical-mechanical polishing

• US 6,068,879 A
• Filed: 08/26/1997
• Issued: 05/30/2000
• Est. Priority Date: 08/26/1997
• Status: Expired due to Term
• 

• Current Assignee: Bell Semiconductor, LLC (Hilco Inc. (d/b/a Hilco Global))
• Original Assignee: LSI Logic Corporation (Broadcom, Inc.)
• Inventors: Pasch, Nicholas F.
• Primary Examiner(s): Talbot, Brian K.
• Application Number:
  US08/918,360
• Time in Patent Office: 1,008 Days
• Field of Search: 427/96, 427/97, 427/307, 106/14.41, 106/14.42, 106/14.43, 51/308, 216/692, 216/693, 438/959, 438/692
• US Class Current: 216/18
• CPC Class Codes: H01L 21/02074 the processing being a planarization of conductive layers
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]
• CPC Class Codes: Y10S 438/959 Mechanical polishing of wafer

Abstract

A process of inhibiting a corrosion of metal plugs formed in integrated circuits is described. The corrosion inhibiting process includes providing a partially fabricated integrated circuit surface including the metal plugs on a polishing pad to carry out chemical-mechanical polishing, introducing slurry including a corrosion inhibiting compound on the polishing pad in sufficient concentration to inhibit corrosion of the metal plugs of the partially fabricated integrated circuit surface, and polishing the partially fabricated integrated circuit surface.

Claims

1. A process of inhibiting corrosion of metal plugs formed in integrated circuits, comprising:

applying a corrosion inhibiting compound on a partially fabricated integrated circuit surface in a manner allowing the corrosion inhibiting compound to seep into a seam of said metal plug and effectively coat a substantial portion of seam side-walls extending into the metal plug;

contacting the partially fabricated integrated circuit surface including said metal plugs with a polishing pad to carry out chemical-mechanical polishing;

introducing a slurry including a corrosion inhibiting compound on the polishing pad in sufficient concentration to further inhibit corrosion of said metal plugs of said partially fabricated integrated circuit surface; and

polishing said partially fabricated integrated circuit surface including the metal plugs wherein the corrosion inhibiting compound is applied to said partially fabricated integrated circuit surface prior to contacting said partially fabricated integrated circuit surface with the polishing pad.

2. The process of claim 1, wherein the metal plugs comprise contact plugs or via plugs.

3. The process of claim 1, wherein the slurry includes an oxidizing agent and a plurality of abrasive particles.

4. The process of claim 1, wherein the corrosion inhibiting compound is selected from the group consisting of sulfur containing compounds, phosphorous containing compounds and azole containing compounds.

5. The process of claim 4, wherein the corrosion inhibiting compound is selected from the group consisting of triazoles, pyrazoles, imidazole, isoxazoles, oxazoles, isothiazoles and thiazoles.

6. The process of claim 1, wherein the concentration of the corrosion inhibiting compound ranges from between about 0.0001% (in volume) to a value that is limited by the solubility of the corrosion inhibiting compound in the slurry at operating conditions.

7. The process of claim 4, wherein the corrosion inhibiting compound includes at least one compound selected from the group consisting of acetodisphosphonic acid, nitrilo tris methylene phosphonic acid, methylamino dimethylene phosphonic acid, hydroxyethylidene diphosphonic acid, zinc sulfate, calcium sulfonate, magnesium sulfate heptahydrate, and sulfonated styrene.

8. The process of claim 6, wherein the corrosion inhibiting composition includes at least one of 2-mercaptothiazole, 2-mercaptobenzothiazole, benzothiazole, benzotriazole, and tolyltriazole present in a concentration of between about 0.001% (in volume) and about 2% (in volume).

9. The process of claim 3, wherein said oxidizing agent includes at least one compound selected from the group consisting of ferric nitrate, hydrogen peroxide, potassium hydroxide and potassium iodate.

10. The process of claim 3, wherein the plurality of abrasive particles include at least one compound selected from the group consisting of alumina, silicon dioxide, and cerium oxide.

16. The process of claim 10, wherein the corrosion inhibiting compound includes at least one compound selected from the group consisting of acetodisphosphonic acid, nitrilo tris methylene phosphonic acid, methylamino dimethylene phosphonic acid, hydroxyethylidene diphosphonic acid, zinc sulfate, calcium sulfonate, magnesium sulfate heptahydrate and sulfonated styrene.

11. A process of inhibiting corrosion of metal plugs formed in integrated circuits, comprising:

providing a partially fabricated integrated circuit surface including said metal plugs;

polishing the partially fabricated integrated circuit surface including the metal plugs with a slurry;

introducing a fining solution including a corrosion inhibiting compound on a polishing pad in sufficient concentration to inhibit corrosion of said metal plugs of said partially fabricated integrated circuit; and

fine polishing a surface of said partially fabricated integrated circuit including said metal plugs.

12. The process of claim 11, wherein the fining solution includes between about 1% and about 3% (in volume) ammonium hydroxide in deionized water.

13. The process of claim 11, wherein the corrosion inhibiting compound is selected from the group consisting of sulfur containing compounds, phosphorous containing compounds and azole containing compounds.

14. The process of claim 13, wherein the corrosion inhibiting compound is selected from the group consisting of triazoles, pyrazoles, imidazole, isoxazoles, oxazoles, isothiazoles and thiazoles.

15. The process of claim 11, wherein the concentration of the corrosion inhibiting compound ranges from between about 0.0001% (in volume) to a value that is limited by the solubility of the corrosion inhibiting compound in the fining solution at operating conditions.

17. The process of claim 15, wherein the corrosion inhibiting composition includes at least one of 2-mercaptothiazole, 2-mercaptobenzothiazole, benzothiazole, benzotriazole, and tolyltriazole present in a concentration of between about 0.001% (in volume) and about 2% (in volume).

21. A process of inhibiting corrosion of metal plugs formed in integrated circuits, comprising:

providing a partially fabricated integrated circuit surface including said metal plugs; and

soaking said partially fabricated integrated circuit surface in a rinsing solution including a corrosion inhibiting compound in sufficient concentration to inhibit corrosion of said metal plugs of said partially fabricated integrated circuit surface.

18. The process of claim 21, wherein the rinsing solution includes deionized water.

19. The process of claim 21, wherein the rinsing solution further comprising ammonium hydroxide ranging from between about 0.5% to about 3% in the corrosion inhibiting composition.

20. The process of claim 21, wherein the rinsing solution further comprising between about 0.5% and about 1% by weight of hydrofluoric acid in the corrosion inhibiting composition.

22. The process of claim 21, wherein the rinsing solution comprises a wet storage solution, in which the partially fabricated integrated circuit surface is soaked.

23. The process of claim 21, wherein the corrosion inhibiting compound includes is selected from the group consisting of sulfur containing compounds, phosphorous containing compounds and azole containing compounds.

24. The process of claim 23, wherein the corrosion inhibiting compound is selected from the group consisting of triazoles, pyrazoles, imidazole, isoxazoles, oxazoles, isothiazoles and thiazoles.

25. The process of claim 21, wherein the concentration of the corrosion inhibiting compound ranges from between about 0.0001% (in volume) to a value that is limited by the solubility of the corrosion inhibiting compound in the rinsing solution at operating conditions.

26. The process of claim 23, wherein the corrosion inhibiting compound includes at least one compound selected from the group consisting of acetodisphosphonic acid, nitrilo tris methylene phosphonic acid, methylamino dimethylene phosphonic acid, hydroxyethylidene diphosphonic acid, zinc sulfate, calcium sulfonate, magnesium sulfate heptahydrate and sulfonated styrene.

27. The process of claim 25, wherein the corrosion inhibiting composition includes at least one of 2-mercaptothiazole, 2-mercaptobenzothiazole, benzothiazole, benzotriazole, and tolyltriazole present in a concentration of between about 0.001% (in volume) and about 2% (in volume).

28. A process of inhibiting corrosion of metal plugs formed in integrated circuits, comprising:

providing a partially fabricated integrated circuit surface including said metal plugs; and

introducing in a wafer scrubber a cleaning solution including a corrosion inhibiting compound in sufficient concentration to inhibit corrosion of said metal plugs of said integrated circuit.

29. The process of claim 28, wherein the cleaning solution includes ammonium hydroxide.

30. The process of claim 28, wherein the corrosion inhibiting compound is selected from the group consisting of sulfur containing compounds, phosphorous containing compounds and azole containing compounds.

31. The process of claim 30, wherein the corrosion inhibiting compound is selected from the group consisting of triazoles, pyrazoles, imidazole, isoxazoles, oxazoles, isothiazoles and thiazoles.

32. The process of claim 28, wherein the concentration of the corrosion inhibiting compound ranges from between about 0.0001% (in volume) to a value that is limited by the solubility of the corrosion inhibiting the cleaning solution at operating conditions.

33. The process of claim 30, wherein the corrosion inhibiting compound includes at least one compound selected from the group consisting of acetodisphosphonic acid, nitrilo tris methylene phosphonic acid, methylamino dimethylene phosphonic acid, hydroxyethylidene diphosphonic acid, zinc sulfate, calcium sulfonate, magnesium sulfate heptahydrate and sulfonated styrene.

34. The process of claim 32, wherein the corrosion inhibiting composition is between about 0.001% (in volume) and about 2% (in volume).