System for the preferential removal of silicon oxide

1. A method of planarizing or polishing a composite substrate comprising (i) contacting the substrate comprising nitrides and oxides with a polishing system comprising (a) polishing composition comprising (1) about 0.5 wt. % or more of a source of fluoride ions, (2) about 1 wt. % or more of an amine, (3) about 0.1 wt. % or more of a base, and (4) water, and (b) an abrasive, and (ii) removing at least a portion of the substrate to polish the substrate.

2. The method of claim 1 , wherein the substrate is a composite semiconductor substrate.

3. The method of claim 1 , wherein the substrate is planarized or polished after having undergone a shallow trench isolation process.

4. The method of claim 1 , wherein the system has a pH of about 7-14.

5. The method of claim 1 , wherein the abrasive is selected from the group consisting of alumina, silica, titania, ceria, zirconia, germania, magnesia, coformed products thereof, and mixtures thereof.

6. The method of claim 5 , wherein the abrasive is silica.

7. The method of claim 1 , wherein the abrasive is present in the polishing composition in a concentration of about 0.1 wt. % or more.

8. The method of claim 1 , wherein the abrasive is fixed in or on a polishing pad.

9. The method of claim 1 , wherein the source of fluoride ions is selected from the group consisting of fluoride salts, fluoride acids, fluoride metal complexes, and combinations thereof.

10. The method of claim 1 , wherein the amine is an amino alcohol.

11. The method of claim 10 , wherein the amine is 2-dimethylamino-2-methyl-1-propanol.

12. The method of claim 1 , wherein the base is selected from the group consisting of inorganic hydroxide bases and carbonate bases.

13. The method of claim 12 , wherein the base is selected from the group consisting of potassium hydroxide, sodium hydroxide, ammonium hydroxide, cesium hydroxide, sodium carbonate, and mixtures thereof.

14. The method of claim 1 , wherein the system further comprises a quaternary ammonium compound.

15. The method of claim 1 , wherein the planarization or polishing of the composite substrate takes place with a polishing selectivity of oxide:nitride of about 2:1 or more.

16. The method of claim 1 , wherein the composition comprises a cationic species that reduces nitride removal from the composite substrate.

17. The method of claim 1 , wherein the fluoride ions comprise less than about 100% active fluoride ions.

18. The method of claim 1 , wherein the slurry has a free alkalinity value of about 0.001-0.15 mol/l.

19. The method of claim 1 , wherein the slurry has a total alkalinity value of about 0.005-0.2 mol/l.

20. The method of claim 1 , wherein the slurry is mixed prior to delivery to the surface of the substrate.

21. The method of claim 1 , wherein the slurry is mixed on the surface of the polishing pad.

22. A method of planarizing or polishing a composite substrate comprising (i) contacting the substrate with a polishing composition comprising (a) about 0.5 wt. % to about 10 wt. % of a source of fluoride ions, (b) about 1% to about 10 wt. % of an amine, (c) about 0.5 wt. % to about 8 wt. % of a base, (d) about 0.1 wt. % to about 30 wt. % of an abrasive, and (e) water, and (ii) removing at least a portion of the substrate to polish the substrate.

23. The method of claim 22 , wherein the composition has a pH of about 7-14.

24. The method of claim 22 , wherein the abrasive is selected from the group consisting of alumina, silica, titania, ceria, zirconia, germania, magnesia, coformed products thereof, and mixtures thereof.

25. The method of claim 24 , wherein the abrasive is silica.

26. The method of claim 22 , wherein the source of fluoride ions is selected from the group consisting of fluoride salts, fluoride acids, fluoride metal complexes, and combinations thereof.

27. The method of claim 22 , wherein the amine is an amino alcohol.

28. The method of claim 27 , wherein the amine is 2-dimethylamino-2-methyl-1-propanol.

29. The method of claim 22 , wherein the base is selected from the group consisting of potassium hydroxide, sodium hydroxide, ammonium hydroxide, cesium hydroxide, sodium carbonate, and mixtures thereof.

30. The method of claim 22 , wherein the composition further comprises a quaternary ammonium compound.

31. The method of claim 22 , wherein the composition has a polishing selectivity of oxide:nitride of about 2:1 or more.