Formulations for the removal of particles generated by cerium-containing solutions

1. An aqueous composition comprising:

an acid having a pKa of less than 4, wherein the acid is a strong acid having a pKa of less than 1.5 selected from the group consisting of nitric acid, sulfuric acid, perchloric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, methanesulfonic acid, and combinations thereof, and is present in an amount ranging from 0.1 to 15 wt. % based on the total weight of the composition;

a reducing agent, wherein the reducing agent is present in an amount ranging from 0.1 to 10 wt. % based on the total weight of the composition;

a salt of the strong acid; and

at least 65 wt. % water, the composition substantially devoid of fluoride ions, wherein when in contact with a surface of a microelectronic device including metal gate material and having lanthanoid-containing solids present thereon, the composition dissolves at least some of the lanthanoid-containing solids without substantially removing metal gate material present on the substrate.

2. The aqueous composition of claim 1 , wherein the strong acid is nitric acid, sulfuric acid, or a combination of nitric acid and sulfuric acid.

3. The aqueous composition of claim 1 , wherein the acid is present in an amount ranging from 0.1 to 5 wt. % based on the total weight of the composition.

4. An aqueous composition comprising:

an acid having a pKa of less than 4, wherein the acid is present in an amount ranging from 0.1 to 15 wt. % based on the total weight of the composition;

a reducing agent, wherein the reducing agent is present in an amount ranging from 0.1 to 10 wt. % based on the total weight of the composition; and

at least 65 wt. % water,

wherein the acid is a weak acid having a pKa in a range from about 1.5 to about 4, wherein the weak acid is selected from the group consisting of nitrous acid, phosphorous acid, cyanic acid, formic acid, glyceric acid, glycolic acid, lactic acid, pyruvic acid, mandelic acid, succinic acid, malonic acid, and combinations thereof, and

wherein when in contact with a surface of a microelectronic device having lanthanoid-containing solids present thereon, the composition dissolves at least some of the lanthanoid-containing solids.

5. The aqueous composition of claim 4 , wherein the weak acid is formic acid.

6. The aqueous composition of claim 1 , wherein the reducing agent is present in an amount ranging from 0.1 to 5 wt. % based on the total weight of the composition.

7. The aqueous composition of claim 1 , wherein the reducing agent is selected from the group consisting of ascorbic acid, borane-pyridine, borane-morpholine, hydroxylamine sulfate, hydroxylamine hydrochloride, ammonium nitrite, ammonium sulfite, ammonium hydrogen sulfite, hydrazine sulfate, hydrazine hydrochloride, ammonium hydrogen sulfide, diethyl malonate, hydroquinone, ammonium metabisulfite, polyphenon 60, glucose, ammonium citrate, hydrogen, formic acid, oxalic acid, acetaldehyde, hydrogen iodide, ammonium phosphite, ammonium hydrogen phosphite, hypophosphorous acid, and combinations thereof.

8. The aqueous composition of claim 1 , wherein the reducing agent is ascorbic acid.

9. The aqueous composition of claim 1 , wherein the reducing agent is polyphenon 60.

10. The aqueous composition of claim 1 , wherein the lanthanoid-containing solids comprises cerium-containing solids, and wherein when in contact with the surface of a microelectronic device having cerium-containing solids present thereon, the composition dissolves at least some of the cerium-containing solids.

11. The aqueous composition of claim 4 , wherein the reducing agent is present in an amount ranging from 0.1 to 5 wt. % based on the total weight of the composition.

12. The aqueous composition of claim 4 , wherein the reducing agent is selected from the group consisting of ascorbic acid, borane-pyridine, borane-morpholine, hydroxylamine sulfate, hydroxylamine hydrochloride, ammonium nitrite, ammonium sulfite, ammonium hydrogen sulfite, hydrazine sulfate, hydrazine hydrochloride, ammonium hydrogen sulfide, diethyl malonate, hydroquinone, ammonium metabisulfite, polyphenon 60, glucose, ammonium citrate, hydrogen, formic acid, oxalic acid, acetaldehyde, hydrogen iodide, ammonium phosphite, ammonium hydrogen phosphite, hypophosphorous acid, and combinations thereof.

13. The aqueous composition of claim 4 , wherein the reducing agent is ascorbic acid.

14. The aqueous composition of claim 4 , wherein the reducing agent is polyphenon 60.

15. The aqueous composition of claim 4 , wherein the lanthanoid-containing solids comprises cerium-containing solids, and wherein when in contact with the surface of a microelectronic device having cerium-containing solids present thereon, the composition dissolves at least some of the cerium-containing solids.