CMP compositions selective for oxide and nitride with high removal rate and low defectivity
The invention relates to a chemical-mechanical polishing composition comprising a ceria abrasive, cations of one or more lanthanide metals, one or more nonionic polymers, water, and optionally one or more additives. The invention further relates to a method of chemically-mechanically polishing a substrate with the inventive chemical-mechanical polishing composition. Typically, the substrate comprises one or more of silicon oxide, silicon nitride, and polysilicon.
1. A chemical-mechanical polishing composition comprising:
(a) a ceria abrasive,
(b) cations of one or more lanthanide metals,
(c) one or more nonionic polymers selected from the group consisting of alkylene oxide, containing polymers, acrylamide polymers, and mixtures thereof,
(d) one or more phosphinocarboxylate polymers, and
(e) water.
2. The polishing composition of claim 1 , wherein the ceria abrasive is a wet-process ceria and is present in an amount of about 0.1 wt.% to about 10 wt.% of the polishing composition.
3. The polishing composition of claim 1 , wherein the cations of one or more lanthanide metals are present in a concentration of about 10 ppm to about 5,000 ppm.
4. The polishing composition of claim 1 , wherein the nonionic polymers are one or more alkylene oxide containing polymers and are present in an amount of 0.05 wt.% to about 5 wt.% of the polishing composition.
5. The polishing composition of claim 4 , wherein the average molecular weight of the alkylene oxide containing polymers is about 100,000 g/mol or less.
6. The polishing composition of claim 5 , wherein the average molecular weight of the alkylene oxide containing polymers is about 10,000 g/mol or less.
7. The polishing composition of claim 4 , wherein the alkylene oxide containing polymers are selected from the group consisting of polyethylene glycols, polypropylene glycols, polyetheramines, ethoxylated acetylenic diols, and mixtures thereof.
8. The polishing composition of claim 4 , wherein the alkylene oxide containing polymers are selected from the group consisting of copolymers of polyethylene glycol and polypropylene glycol.
9. The polishing composition of claim 8 , wherein the copolymers of polyethylene glycol and polypropylene glycol have an average molecular weight of about 1,100 g/mol.
10. The polishing composition of claim 1 , wherein the one or more nonionic polymers is an acrylamide polymer.
11. The polishing composition of claim 10 , wherein the one or more acrylamide polymers is polyacrylamide.
12. The polishing composition of claim 1 , further comprising one or more anionic polymeric complexing agents.
13. The polishing composition of claim 12 , wherein the one or more anionic polymeric complexing agents is selected from the group consisting of polyacrylic acid, poly(methacrylic) acid, and mixtures thereof.
14. The polishing composition of claim 1 , further comprising one or more phosphonic acids.
15. The polishing composition of claims 1 , further comprising one or more sulfonic acids.
16. The polishing composition of claim 1 , further comprising polyvinylpyrrolidone.