Titanium dioxide containing ruthenium chemical mechanical polishing slurry
A chemical mechanical polishing composition for polishing a ruthenium containing substrate comprises, consists of, or consists essentially of a water based liquid carrier; titanium oxide particles dispersed in the liquid carrier, the titanium oxide particles including rutile and anatase such that an x-ray diffraction pattern of the titanium oxide particles has a ratio X:Y greater than about 0.05, wherein X represents an intensity of a peak in the x-ray diffraction pattern having a d-spacing of about 3.24 Å and Y represents an intensity of a peak in the x-ray diffraction pattern having a d-spacing of about 3.51 Å; and a pH in a range from about 7 to about 10. Optional embodiments further include a pH buffer having a pK a in a range from about 6 to about 9.
1. A chemical mechanical polishing composition comprising:
a water based liquid carrier;
titanium oxide particles dispersed in the liquid carrier, the titanium oxide particles including rutile and anatase such that an x-ray diffraction pattern of the titanium oxide particles has a ratio X:Y of about 0.05 to about 0.5, wherein X represents an intensity of a peak in the x-ray diffraction pattern having a d-spacing of about 3.24 Å and Y represents an intensity of a peak in the x-ray diffraction pattern having a d-spacing of about 3.51 Å; and
a pH in a range from about 7 to about 10.
2. The composition of claim 1 , wherein the pH is in a range from about 7.5 to about 9.5.
3. The composition of claim 1 , further comprising a pH buffer having a pK a in a range from about 6 to about 9.
4. The composition of claim 1 , comprising from about 0.05 wt. % to about 1 wt. % of the titanium oxide particles.
5. The composition of claim 1 , further comprising a peroxide compound.
6. A method for polishing a ruthenium containing substrate, the method comprising:
(a) contacting the substrate with the polishing composition of claim 1 ;
(b) moving the polishing composition relative to the substrate; and
(c) abrading the substrate to remove a portion of the ruthenium layer from the substrate and thereby polish the substrate.
7. A chemical mechanical polishing composition comprising:
a water based liquid carrier;
titanium oxide particles dispersed in the liquid carrier, the titanium oxide particles including rutile and anatase such that an x-ray diffraction pattern of the titanium oxide particles has a ratio X:Y of greater than about 0.05, wherein X represents an intensity of a peak in the x-ray diffraction pattern having a d-spacing of about 3.24 Å and Y represents an intensity of a peak in the x-ray diffraction pattern having a d-spacing of about 3.51 Å;
a pH in a range from about 7 to about 10; and
a pH buffer having a pK a in a range from about 6 to about 9.
8. The composition of claim 7 , wherein the pH buffer is selected from the group consisting of citric acid, bis tris methane, tris(hydroxymethyl)aminomethane, tricine (tris glycine), diglycine, dipotassium hydrogen phosphate, triethanolamine, (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) (HEPES), N-(2-Hydroxyethyl)piperazine-N′-(3-propanesulfonic acid) (HEPPS), diethanolamine, bicine, N-Tris(hydroxymethyl)methyl-3-aminopropanesulfonic acid (TAPS), N-Methyldiethanolamine, 2-amino-2-methyl-1,3-propanediol (AMPD), and mixtures thereof.
9. The composition of claim 7 , wherein the pH buffer has a pK a in a range from about 7.5 to about 9.
10. The composition of claim 9 , wherein the pH buffer is selected from the group consisting of tris(hydroxymethyl)aminomethane, tricine (tris glycine), diglycine, triethanolamine, (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) (HEPES), N-(2-Hydroxyethyl)piperazine-N′-(3-propanesulfonic acid) (HEPPS), diethanolamine, bicine, N-Tris(hydroxymethyOmethyl-3-aminopropanesulfonic acid (TAPS), N-Methyldiethanolamine, 2-amino-2-methyl-1,3-propanediol (AMPD), and mixtures thereof.
11. The composition of claim 7 , wherein the pH buffer has a pK a in a range from about 8.0 to about 8.5.
12. The composition of claim 7 wherein the pH buffer is tris(hydroxymethyl)aminomethane.
13. The composition of claim 7 , wherein the pH is in a range from about 7.5 to about 9.5.
14. The composition of claim 7 , comprising from about 0.05 wt. % to about 1 wt. % of the titanium oxide particles.
15. The composition of claim 7 , wherein a concentration of the pH buffer is in a range from about 0.3 mM to about 30 mM.
16. The composition of claim 7 , wherein the pH is in a range from about 7.5 to about 9.5 and the pH buffer has a pK a in a range from about 7.5 to about 9.
17. The composition of claim 7 , wherein the titanium oxide particles have a ratio X:Y of greater than about 1.
18. The composition of claim 7 , wherein the titanium oxide particles have a ratio X:Y of greater than about 10.
19. The composition of claim 7 , wherein the titanium oxide is substantially pure rutile.
20. A method for polishing a ruthenium containing substrate, the method comprising:
(a) contacting the substrate with the polishing composition of claim 7 ;
(b) moving the polishing composition relative to the substrate; and
(c) abrading the substrate to remove a portion of the ruthenium layer from the substrate and thereby polish the substrate.
21. The method of claim 20 , wherein:
said moving in (b) comprises moving the polishing composition relative to the substrate and a polishing pad; and
said abrading in (c) does not stain the polishing pad.