Composition and slurry useful for metal CMP

• US 5,980,775 A
• Filed: 04/08/1997
• Issued: 11/09/1999
• Est. Priority Date: 11/26/1996
• Status: Expired due to Term

• Current Assignee: Cabot Microelectronics Corporation (Entegris Incorporated)
• Original Assignee: Cabot Corporation
• Inventors: Streinz, Christopher C., Grumbine, Steven K., Mueller, Brian L.
• Primary Examiner(s): Breneman, Bruce
• Assistant Examiner(s): Ahmed, Shamim
• Application Number:
  US08/827,918
• Time in Patent Office: 945 Days
• Field of Search: 438/692, 438/693, 252/79.1, 216/89
• US Class Current: 252/79.1
• CPC Class Codes: C09G 1/02 containing abrasives or grinding agents abrasives as such C09K3/14; polishing of semi-conductors H01L
• CPC Class Codes: C23F 3/00 Brightening metals by chemical means
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]

Abstract

A chemical mechanical polishing composition comprising an oxidizing agent at least one catalyst having multiple oxidation states, and at least one stabilizer, the composition being useful when combined with an abrasive or with an abrasive pad to remove metal layers from a substrate.

Claims

1. A chemical mechanical polishing composition comprising the admixture of:

a first component including at least one oxidizing agent; and

a second component that includes the product of the mixture of at least one catalyst having multiple oxidation states and at least one stabilizer.

2. The chemical mechanical polishing composition of claim 1 wherein the stabilizer is an organic acid, an inorganic acid, a nitrile, or mixtures thereof.

3. The chemical mechanical polishing composition of claim 1 wherein the stabilizer is an organic acid.

4. The chemical mechanical polishing composition of claim 2 wherein the stabilizer is selected from the group phosphoric acid, phthalic acid, citric acid, malonic acid, phosphonic acid, oxalic acid, adipic acid, benzonitrile, or mixtures thereof.

5. The chemical mechanical polishing composition of claim 4 wherein the stabilizer is the admixture of from about 0 equivalents per catalyst to about 3 equivalents per catalyst of oxalic acid, and from about 0.2 to about 1.0 weight percent adipic acid.

6. The chemical mechanical polishing composition of claim 4 wherein the stabilizer is from about 2 equivalents per catalyst to about 15 equivalents per catalyst of malonic acid.

7. The chemical mechanical polishing composition of claim 4 wherein the stabilizer is from about 3 equivalents per catalyst to about 3.0 weight percent phthalic acid.

8. The chemical mechanical composition of claim 1 wherein the oxidizing agent is an organic peroxide compound, an inorganic peroxide compound, or mixtures thereof.

9. The chemical mechanical composition of claim 1 wherein the oxidizing agent is from about 0.5 to about 10.0 weight percent hydrogen peroxide.

10. The chemical mechanical composition of claim 1 including at least one abrasive to produce a chemical mechanical polishing slurry.

11. The chemical mechanical polishing slurry of claim 10 wherein the abrasive is at least one metal oxide abrasive selected from the group including alumina, ceria, germania, silica, titania, zirconia, or mixtures thereof.

12. The chemical mechanical polishing slurry of claim 11 wherein the metal oxide abrasive is from about 1.0 to about 20.0 weight percent alumina.

13. The chemical mechanical composition of claim 1 wherein the catalyst is an iron catalyst selected from the group consisting of inorganic iron compounds and organic iron compounds having multiple oxidation states.

14. The chemical mechanical polishing composition of claim 13 wherein the iron catalyst is from about 0.01 to about 0.5 weight percent ferric nitrate.

15. A chemical mechanical polishing slurry comprising:

from about 3.0 to about 7.0 weight percent silica;

from about 0.5 to about 10.0 weight percent hydrogen peroxide; and

the product of the mixture of from about 0.01 to about 0.05 weight percent ferric nitrate catalyst and from about 2 equivalents per catalyst to about 15 equivalents per catalyst of malonic acid.

16. The chemical mechanical polishing slurry of claim 15 wherein the silica has a surface area of from about 120 m² /g to about 200 m² /g.

17. A method for polishing a substrate including at least one metal layer comprising the steps of:

(a) preparing an admixture of a first component including at least one oxidizing agent, and a second component including the product of the mixture of at least one catalyst having multiple oxidation states and at least one stabilizer, and deionized water to produce a chemical mechanical polishing composition;

(b) applying the chemical mechanical polishing composition to the substrate; and

(c) removing at least a portion of the metal layer from the substrate by bringing a pad into contact with the substrate and moving the pad in relation to the substrate.

18. The method of claim 17 wherein the substrate includes a tungsten containing metal layer and a titanium nitride containing metal layer and wherein at least a portion of the tungsten layer and a portion of the titanium nitride layer is removed in step (c).

19. The method of claim 17 wherein the stabilizer is an organic acid, an inorganic acid, a nitrile, or mixtures thereof.

20. The method of claim 19 wherein the stabilizer is an organic acid selected from the group phosphoric acid, phthalic acid, citric acid, malonic acid, phosphinic acid, oxalic acid, adipic acid, benzonitrile, or mixtures thereof.

21. The method of claim 20 wherein the stabilizer is selected from a mixture of from about 0 equivalents per catalyst to about 3 equivalents per catalyst of oxalic acid and from about 0.2 to about 1.0 weight percent adipic acid, from about 2 equivalents per catalyst to about 15 equivalents per catalyst of malonic acid, and from about 3 equivalents per catalyst to about 3.0 weight percent phthalic acid.

22. The method of claim 21 wherein the oxidizing agent is from about 0.5 to about 10.0 weight percent hydrogen peroxide, and the catalyst is from about 0.01 to about 0.5 weight percent ferric nitrate.

23. The method of claim 17 wherein the polishing composition further comprises at least one metal oxide abrasive.

24. The method of claim 23 wherein the metal oxide abrasive is alumina.

25. The method of claim 23 wherein the metal oxide abrasive is silica.

26. The method of claim 25 wherein the silica has a surface area of from about 120 m₂ /g to about 200 m₂ /g.