System for the preferential removal of silicon oxide
A system, composition, and a method for planarizing or polishing a composite substrate are provided. The planarizing or polishing system comprises (i) a polishing composition comprising (a) about 0.5 wt. % or more of fluoride 5 ions, (b) about 1 wt. % or more of an amine, (c) about 0.1 wt. % or more of a base, and (d) water, and (ii) an abrasive. The present invention also provides a method of planarizing or polishing a composite substrate comprising contacting the substrate with a system comprising (i) a polishing composition comprising (a) about 0.5 wt. % or more of fluoride ions, (b) about 1 wt. % or more of an amine, (c) about 0.1 wt. % or more of a base, and (d) water, and (ii) an abrasive.
1. A chemical-mechanical polishing composition for planarizing or polishing a composite substrate comprising (a) about 0.5 wt. % to about 10 wt. % of a source of fluoride ions, (b) about 1 wt % 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.
2. The composition of claim 1 , wherein the composition system has a pH of about 7–14.
3. The composition 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.
4. The composition of claim 3 , wherein the abrasive is silica.
5. The composition of claim 1 , wherein the fluoride ions are from a source of fluoride ions selected from the group consisting of fluoride salts, fluoride acids, fluoride metal complexes, and combinations thereof.
6. The composition of claim 1 , wherein the amine is an amino alcohol.
7. The composition of claim 6 , wherein the amine is 2-dimethylamino-2-methyl-1-propanol.
8. The composition of claim 1 , wherein the base is selected from the group consisting of inorganic hydroxide bases and carbonate bases.
9. The composition of claim 8 , wherein the base is selected from the group consisting of potassium hydroxide, sodium hydroxide, ammonium hydroxide, cesium hydroxide, sodium carbonate, and mixtures thereof.
10. The composition of claim 1 , wherein the composition further comprises a quaternary ammonium compound.
11. The composition of claim 1 , wherein the composition has a polishing selectivity of oxide:nitride of about 2:1 or more.
12. The composition of claim 1 , wherein the composition comprises a cationic species that reduces nitride removal from the composite substrate.
13. The composition of claim 1 , wherein the fluoride ions comprise less than about 100% active fluoride ions.
14. The composition of claim 1 , wherein the composition has a free alkalinity value of about 0.001–0.15 mol/l.
15. The composition system of claim 1 , wherein the composition has a total alkalinity value of about 0.005–0.2 mol/l.