Colloidal silica based chemical mechanical polishing slurry

• US 20060124593A1
• Filed: 05/31/2005
• Published: 06/15/2006
• Est. Priority Date: 12/13/2004
• Status: Abandoned Application

• Current Assignee: Planar Solutions LLC (Fujifilm Holdings Corporation)
• Original Assignee: Planar Solutions LLC (Fujifilm Holdings Corporation)
• Inventors: Koontz, Nichole R., Delbridge, Ken A., Sayles, Gerome J., Moyaerts, Gert R.M., Mohseni, Saeed H., Mahulikar, Deepak
• Application Number:
  US11/141,162
• Publication Number:
  US 20060124593A1
• Time in Patent Office: Days
• US Class Current: 216/88
• 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
• CPC Class Codes: C09K 3/1472 Non-aqueous liquid suspensions
• CPC Class Codes: C23F 3/04 Heavy metals
• CPC Class Codes: H01L 21/30625 With simultaneous mechanical treatment, e.g. mechanico-chemical polishing
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]

Abstract

A composition for chemical mechanical polishing a surface of a substrate having a plurality of ultra high purity sol gel processed colloidal silica particles for chemical mechanical polishing having alkali metals Li, Na, K, Rb, Cs, Fr and a combination thereof, at a total alkali concentration of about 300 ppb or less, with the proviso that the concentration of Na, if present, is less than 200 ppb; and a medium for suspending the particles is provided. Also, provided are methods of chemical mechanical polishing which included a step of contacting a substrate and a composition according to the present invention. The contacting is carried out at a temperature and for a period of time sufficient to planarize the substrate.

Claims

1. A composition for chemical mechanical polishing a surface of a substrate comprising:

a plurality of ultra high purity sol gel processed colloidal silica particles having at least one alkali metal selected from a group consisting of;

Li, Na, K, Rb, Cs, Fr and a combination thereof, at a total alkali concentration of about 300 ppb or less, with the proviso that the concentration of Na, if present, is about 200 ppb or less; and

a medium for suspending said particles.

2. The composition of claim 1, wherein said alkali metal includes at least one heavy alkali metal selected from a group consisting of:

Rb, Cs, Fr, and a mixture thereof, wherein said heavy alkali metal is present at a concentration about 100 ppb or less and wherein the concentration of Na is about 100 ppb or less.

3. The composition of claim 2, wherein said concentration of Na is about 50 ppb or less.

4. The composition of claim 2, wherein said heavy alkali metal is present at a concentration of about 75 ppb or less and wherein the concentration Na is about 50 ppb or less.

5. The composition of claim 2, wherein said heavy alkali metal is present at a concentration of 50 ppb or less.

6. The composition of claim 1, wherein said sol gel silica particles comprise from about 19 wt. % to about 24 wt. % of the total weight of said composition.

7. The composition of claim 1, wherein 0.5% to 49% of said particles have a particle size from about 38 to about 200 nm.

8. The composition of claim 1, wherein at least 50% the particles have a particle size from about 30 nm to about 100 nm.

9. The composition of claim 1, wherein said particles have a particle shape selected from the group consisting of:

an aggregated shape, a cocoon shape, and a spherical shape.

10. The composition of claim 1, wherein said particles have a surface area from about 80 m²/g to about 90 m²/g.

11. The composition of claim 1, wherein said particles have a mean particle size from about 60 nm to about 200 nm.

12. The composition of claim 1, wherein said sol gel silica particles have a primary particle size from about 10 nm to about 50 nm and a secondary particle size from about 20 nm to about 150 nm.

13. The composition of claim 1, wherein said particles have a total alkali metal concentration of about 250 ppb or less and wherein the concentration of Na is 100 ppb or less.

14. The composition of claim 1, wherein said particles have a total alkali metal concentration of about 200 ppb or less and wherein the concentration of Na is 50 ppb or less.

15. The composition of claim 1, wherein said particles have a total alkali metal concentration of about 150 ppb or less and wherein the concentration of Na is 50 ppb or less.

16. The composition of claim 1, wherein said particles have a total alkali metal concentration of about 100 ppb or less and wherein the concentration of Na is 50 ppb or less.

20. The composition of claim 1, further comprising an additive selected from the group consisting of:

a carboxylic acid and a mixture of carboxylic acids, present in a concentration of about 0.01 wt. % to about 0.9 wt. %;

an oxidizer, present in a concentration of about 10 ppm to about 2,500 ppm;

a corrosion inhibitor, present in the range of about 10 ppm to about 1000 ppm; and

any combinations thereof.

21. The composition of claim 1, wherein said composition is in a form selected from the group consisting of:

emulsion, colloidal suspension, solution and slurry.

22. The composition of claim 1, wherein said medium is from about 81 wt. % to about 86 wt. % of the total weight of said composition.

23. The composition of claim 1, wherein said medium is selected from the group consisting of:

water, an organic solvent and a mixture thereof.

24. The composition of claim 1, wherein said medium has a pH of about 9.0 to about 11.

17. The composition of claim 17, further comprising a surfactant selected from the group consisting of:

anionic, cationic, non-ionic and amphoteric surfactants.

19. The composition of claim 17, wherein said surfactant is present in a concentration of about 10 ppm to about 1000 ppm of the total weight of the composition.

18. The composition of claim 18, wherein said surfactant is an alkoxylated non-ionic surfactant.

25. A method of chemical mechanical polishing a substrate, comprising the step of:

contacting said substrate and a plurality of ultra high purity sol gel processed colloidal silica particles for chemical mechanical polishing having at least one alkali metal selected from a group consisting of;

Li, Na, K, Rb, Cs, Fr and a combination thereof, at a total alkali concentration of about 300 ppb or less, with the proviso that the concentration of Na, if present, is less than 200 ppb; and

a medium for suspending said particles;

wherein said contacting is carried out at a temperature and for a period of time sufficient to planarize said substrate.

26. The method of claim 25, wherein said alkali metals include at least one heavy alkali metal selected from a group consisting of:

Rb, Cs, Fr, and a mixture thereof present at a concentration of about 100 ppb or less and wherein the concentration of Na is about 100 ppb or less.

27. The method of claim 26, wherein said heavy metals are present at a concentration of about 100 ppb or less and a Na concentration of about 50 ppb or less.

28. The method of claim 26, wherein said heavy alkali metals are present at a concentration of about 75 ppb or less and a Na concentration of about 50 ppb or less.

29. The method of claim 26, wherein said heavy alkali metals are present at a concentration of about 50 ppb or less.

30. The method of claim 25, wherein said sol gel silica particles comprise from about 19 wt. % to about 24 wt. % of the total weight of said composition.

31. The method of claim 25, wherein said particles have a surface area from about 80 m²/g to about 90 m²/g.

32. The method of claim 25, wherein at least 50% the particles have a particle size from about 30 nm to about 100 nm.

33. The method of claim 25, wherein 0.5% to 49% of said particles have a particle size from about 38 to about 200 nm.

34. The method of claim 25, wherein said particles have a particle shape selected from the group consisting of:

an aggregated shape, a cocoon shape, and a spherical shape.

35. The method of claim 25, wherein said particles have an alkali metal concentration of about 250 ppb or less and wherein the concentration of Na is 100 ppb or less.

36. The method of claim 25, wherein said particles have an alkali metal concentration of about 200 ppb or less and wherein the concentration of Na is about 100 ppb or less.

37. The method of claim 25, wherein said particles have an alkali metal concentration of about 150 ppb or less and wherein the concentration of Na is about 50 ppb or less.

38. The method of claim 25, wherein said particles have an alkali metal concentration of about 100 ppb or less and wherein the concentration of Na, if present, is 50 or less.

39. The method of claim 25, further comprising a surfactant selected from the group consisting of:

anionic, cationic, non-ionic and amphoteric surfactants and a mixture thereof.

40. The composition of claim 39, wherein said surfactant is an alkoxylated non-ionic surfactant.

41. The method of claim 39, wherein the particles further comprise an additive selected from the group consisting of:

a carboxylic acid, present in a concentration of about 0.01 wt. % to about 0.9 wt. %;

an oxidizer, present in a concentration of about 10 ppm to about 1000 ppm;

a corrosion inhibitor, present in the range of about 10 ppm to about 1000 ppm; and

any combinations thereof.

42. The method of claim 25, wherein said composition is in a form selected from the group consisting of:

emulsion, colloidal suspension, solution and slurry.

43. The method of claim 25, wherein said medium is from about 81 wt. % to about 86 wt. % of the total weight of said composition.

44. The method of claim 25, wherein said medium has a pH about 6.7 to about 7.6.

45. The method of claim 25, wherein said medium is selected from the group consisting of:

water, an organic solvent and a mixture thereof.