Polishing composition and method utilizing abrasive particles treated with an aminosilane
View Patent ↗The inventive method comprises chemically-mechanically polishing a substrate with an inventive polishing composition comprising a liquid carrier, a cationic polymer, an acid, and abrasive particles that have been treated with an aminosilane compound.
1. A chemical-mechanical polishing composition for polishing a substrate comprising:
(a) a liquid carrier,
(b) an abrasive suspended in the liquid carrier, wherein the abrasive comprises colloidal silica particles, and wherein the colloidal silica particles have a surface which has been treated with an aminosilane compound,
(c) at least one acidic component having a pKa of about 1 to about 4, wherein the at least one acidic component is present in an amount of about 500 ppm to about 3000 ppm, and
(d) a cationic polymer, wherein the cationic polymer is present in an amount of about 10 ppm to about 100 ppm;
wherein the polishing composition has a pH of about 1 to about 3.5.
2. The polishing composition of claim 1 , wherein the colloidal silica particles are present in the polishing composition in an amount of about 0.1 wt % to about 4 wt %.
3. The polishing composition of claim 1 , wherein the aminosilane compound is selected from the group consisting of a dipodal silane, aminopropyl trialkoxysilane, and bis(trimethoxysilylpropyl)amine.
4. The polishing composition of claim 1 , wherein the colloidal silica particles having a surface which has been treated with the aminosilane compound have a zeta potential of 5 mV or greater.
5. The polishing composition of claim 1 , wherein the aminosilane compound is present in an amount of about 50 ppm to about 500 ppm.
6. The polishing composition of claim 1 , wherein the at least one acidic component is selected from the group consisting of an inorganic acid, a carboxylic acid, an organic phosphonic acid, an acidic heterocyclic compound, 1-hydroxyethylidene-1,1-diphosphonic acid, amino tri(methylene phosphonic acid), a salt thereof, and combinations thereof.
7. The polishing composition of claim 1 , wherein the polishing composition has a pH of about 1.5 to about 3.5.
8. The polishing composition of claim 1 , wherein the cationic polymer is either a monomer of methacryloyloxyethyltrimethylammonium or diallyldimethylammonium.
9. A method of chemically-mechanically polishing a substrate, which method comprises:
(i) contacting a substrate with a chemical-mechanical polishing composition comprising:
(a) a liquid carrier,
(b) an abrasive suspended in the liquid carrier, wherein the abrasive comprises colloidal silica, and wherein the colloidal silica particles have a surface which has been treated with an aminosilane compound,
(c) at least one acidic component having a pKa of about 1 to about 4, wherein the at least one acidic component is present in an amount of about 500 ppm to about 3000 ppm, and
(d) a cationic polymer, wherein the cationic polymer is present in an amount of about 10 ppm to about 100 ppm,
wherein the polishing composition has pH of about 1 to about 3.5,
(ii) moving the polishing composition relative to the substrate, and
(iii) abrading at least a portion of the substrate to polish the substrate.
10. The method of claim 9 , wherein the colloidal silica particles are present in the polishing composition in an amount of about 0.1 wt % to about 4.0 wt %.
11. The method of claim 9 , wherein the colloidal silica particles having a surface which has been treated with the aminosilane compound have a zeta potential of 5 mV or greater.
12. The method of claim 9 , wherein the aminosilane compound is selected from the group consisting of a dipodal silane, aminopropyl trialkoxysilane, and bis(trimethoxysilylpropyl)amine.
13. The method of claim 9 , wherein the aminosilane compound is present in an amount of about 100 ppm to about 500 ppm.
14. The method of claim 9 , wherein the at least one acidic component is selected from the group consisting of an inorganic acid, a carboxylic acid, an organic phosphonic acid, an acidic heterocyclic compound, 1-hydroxyethylidene-1,1-diphosphonic acid, amino tri(methylene phosphonic acid), a salt thereof, and combinations thereof.
15. The method of claim 9 , wherein the polishing composition has a pH of about 1.5 to about 3.5.
16. The method of claim 9 , wherein the cationic polymer is either a monomer of methacryloyloxyethyltrimethylammonium or diallyldimethylammonium.
17. The method of claim 9 , wherein the substrate comprises at least one layer of silicon nitride.
18. The method of claim 17 , wherein the substrate comprises at least one layer of silicon oxide.
19. The method of claim 18 , wherein the silicon nitride is removed from the substrate at a rate greater than that of the silicon oxide.