Slurry composition having tunable dielectric polishing selectivity and method of polishing a substrate

1. A chemical mechanical polishing slurry composition, consisting of, as initial components:

water;

an abrasive, wherein the abrasive is a colloidal silica abrasive;

a halogenated quaternary ammonium compound according to formula (I):

wherein R 8 is selected from a C 1-10 alkyl group and a C 1-10 hydroxyalkyl group; wherein X 1 is a halide selected from chloride, bromide, iodide and fluoride; wherein R 9 , R 10 and R 11 are each independently selected from a saturated or unsaturated C 1-10 alkyl group, a C 1-10 haloalkyl group, a C 6-15 aryl group, a C 6-15 haloaryl group, a C 6-15 arylalkyl group and a C 6-15 haloarylalkyl; and, wherein the anion in formula (I) can be any anion that balances the + charge on the cation in formula (I);

optionally, a diquaternary substance according to formula (II):

wherein each A is independently selected from N and P; wherein R 1 is selected from a saturated or unsaturated C 1 -C 15 alkyl group, a C 6 -C 15 aryl group and a C 6 -C 15 aralkyl group; wherein R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are each independently selected from selected from a hydrogen, a saturated or unsaturated C 1 -C 15 alkyl group, a C 6 -C 15 aryl group, a C 6 -C 15 aralkyl group and a C 6 -C 15 alkaryl group; and, wherein the anion in formula (II) can be any anion or combination of anions that balance the 2+ charge on the cation in formula (II); and,

optionally, a pH adjusting agent selected from phosphoric acid, nitric acid, sulfuric acid, hydrochloric acid, ammonium hydroxide and potassium hydroxide;

wherein the chemical mechanical polishing slurry composition has a pH of 2 to <7.

2. The chemical mechanical polishing slurry composition of claim 1 , wherein the chemical mechanical polishing slurry composition consists of, as initial components:

water;

0.1 to 40 wt % of the colloidal silica abrasive;

0.001 to 1 wt % of the halogenated quaternary ammonium compound according to formula (I);

0 to 1 wt % of the diquaternary substance according to formula (II); and,

optionally, a pH adjusting agent selected from phosphoric acid, nitric acid, sulfuric acid, hydrochloric acid, ammonium hydroxide and potassium hydroxide.

3. The chemical mechanical polishing slurry composition of claim 1 , wherein the chemical mechanical polishing slurry composition consists of, as initial components:

water;

0.1 to 10 wt % of the colloidal silica abrasive;

0.002 to 0.5 wt % of the halogenated quaternary ammonium compound according to formula (I), wherein R 8 is selected from a —(CH 2 ) 2 — group, —CH 2 CHOC group, —(CH 2 ) 3 — group and a —(CH 2 ) 2 —CHOH; wherein X 1 is a halide selected from chloride and bromide; wherein R 9 , R 10 and R 11 are each independently selected from a —CH 3 group and a —CH 2 CH 3 group; and, wherein the anion in formula (I) is selected from a chloride anion and a bromide anion;

0.002 to 0.2 wt % of the diquaternary substance according to formula (II); wherein each A is a N; R 1 is a —(CH 2 ) 4 — group; and, wherein R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are each a —(CH 2 ) 2 CH 3 group; and,

optionally, a pH adjusting agent selected from phosphoric acid, nitric acid, sulfuric acid, hydrochloric acid, ammonium hydroxide and potassium hydroxide.

4. The chemical mechanical polishing slurry composition of claim 1 , wherein the chemical mechanical polishing slurry composition consists of, as initial components:

water;

0.1 to 10 wt % of the colloidal silica abrasive, wherein the colloidal silica abrasive has an average particle size of 20 to 50 nm;

0.01 to 0.2 wt % of the halogenated quaternary ammonium compound according to formula (I), wherein R 8 is selected from a —(CH 2 ) 2 — group, —CH 2 CHOH group, —(CH 2 ) 3 — group and at —(CH 2 ) 2 —CHOH; wherein X 1 is a halide selected from chloride and bromide; wherein R 9 , R 10 and R 11 are each independently selected from a —CH 3 group and a —CH 2 CH 3 group; and, wherein the anion in formula (I) is selected from a chloride anion and a bromide anion;

0.01 to 0.05 wt % of the diquaternary substance according to formula (II); wherein each A is a N; R 1 is a —(CH 2 ) 4 — group; wherein R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are each a —(CH 2 ) 3 CH 3 group; and wherein the anion(s) that balance the 2+ charge on the cation in formula (II) is(are) selected from halide anion(s) and hydroxide anion(s); and

optionally, a pH adjusting agent selected from phosphoric acid, nitric acid, sulfuric acid, hydrochloric acid, ammonium hydroxide and potassium hydroxide.

5. A method for chemical mechanical polishing of a substrate, comprising:

providing a substrate, wherein the substrate comprises at least one of silicon oxide and Si 3 N 4 ;

providing a chemical mechanical polishing slurry composition according to claim 1 , wherein the concentration of the halogenated quaternary ammonium compound according to formula (I) and the concentration of the optional diquaternary substance according to formula (II) is selected to tailor a removal rate exhibited by the chemical mechanical polishing slurry composition for the at least one of silicon oxide and Si 3 N 4 ;

providing a chemical mechanical polishing pad with a polishing surface;

creating dynamic contact at an interface between the polishing surface of the chemical mechanical polishing pad and the substrate with a down force of 0.69 to 34.5 kPa; and

dispensing the chemical mechanical polishing slurry composition onto the chemical mechanical polishing pad at or near the interface between the chemical mechanical polishing pad and the substrate;

wherein the chemical mechanical polishing slurry composition provided has a pH of <7;

wherein the substrate is polished; and, wherein some of the at least one of silicon oxide and Si 3 N 4 is removed from the substrate.

6. The method of claim 5 , wherein the chemical mechanical polishing slurry composition provided contains, as initial components:

water;

0.1 to 10 wt % of the abrasive, wherein the abrasive is a colloidal silica abrasive having an average particle size of 20 to 50 nm;

0.01 to 0.2 wt % of the halogenated quaternary ammonium compound according to formula (I), wherein R 8 is selected from a —(CH 2 ) 2 — group, —CH 2 CHOH group, —(CH 2 ) 3 — group;

wherein X 1 is a halide selected from chloride and bromide; wherein R 9 , R 10 and R 11 are each independently selected from a —CH 3 group and a —CH 2 CH 3 group; and, wherein the anion in formula (I) is selected from a chloride anion and a bromide anion; and,

0.01 to 0.05 wt % of the diquaternary substance according to formula (II); wherein each A is a N; R 1 is a —(CH 2 ) 4 — group; and, wherein R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are each a —(CH 2 ) 3 CH 3 group; and

wherein the chemical mechanical polishing slurry composition provided has a pH of 2 to 4.

7. The method of claim 6 , wherein the substrate comprises silicon oxide and wherein the chemical mechanical polishing slurry composition is tailored to exhibit a silicon oxide removal rate of 200 to 3,000 Å/min.

8. The method of claim 6 , wherein the substrate comprises Si 3 N 4 and wherein the chemical mechanical polishing slurry composition is tailored to exhibit a Si 3 N 4 removal rate or 300 to 2,000 Å/min.

9. The method of claim 6 , wherein the substrate comprises both silicon oxide and Si 3 N 4 and wherein the chemical mechanical polishing slurry composition is tailored to exhibit a removal rate selectivity for silicon oxide to Si 3 N 4 of 1:2 to 10:1.