Chemical mechanical polishing aqueous dispersion, method of preparing the same, chemical mechanical polishing aqueous dispersion preparation kit, and chemical mechanical polishing method

1. A chemical mechanical polishing aqueous dispersion that is used to polish a polishing target that includes a wiring layer that contains tungsten, the chemical mechanical polishing aqueous dispersion comprising:

(A) a cationic water-soluble polymer;

(B) an iron (III) compound; and

(C) colloidal silica having an average particle diameter calculated from a specific surface area determined by the BET method of 10 to 60 nm,

wherein the cationic water-soluble polymer (A) is present in a content (M A ) (mass %) of 0.001 to 0.01 mass %, and the colloidal silica (C) is present in a content (M c ) (mass %) of 1 to 30 mass %,

the content (M A ) (mass %) of the cationic water-soluble polymer (A) and the content (Mc) (mass %) of the colloidal silica (C) satisfying the relationship “M A /M c =0.0001 to 0.003”, and the chemical mechanical polishing aqueous dispersion having a pH of 1 to 2.

2. The chemical mechanical polishing aqueous dispersion according to claim 1 , wherein the cationic water-soluble polymer (A) is a polyethylenimine.

3. The chemical mechanical polishing aqueous dispersion according to claim 1 , wherein the cationic water-soluble polymer (A) has a number average molecular weight of 200 to 1,000,000.

4. The chemical mechanical polishing aqueous dispersion according to claim 1 , wherein the iron (III) compound (B) is ferric nitrate.

5. The chemical mechanical polishing aqueous dispersion according to claim 1 , wherein the content (M B ) (mass %) of the iron (III) compound (B) is 0.01 to 40 mass %.

6. The chemical mechanical polishing aqueous dispersion according to claim 1 , wherein the polishing target includes an insulating film having a via-hole, and a tungsten film formed on the insulating film through a barrier metal film.

7. A chemical mechanical polishing method comprising polishing a polishing target that includes a wiring layer that contains tungsten using the chemical mechanical polishing aqueous dispersion according to claim 1 .

8. A kit for preparing the chemical mechanical polishing aqueous dispersion according to claim 1 , the kit comprising:

a first composition that has a pH of 8 to 11, and includes at least (C) colloidal silica having an average particle diameter calculated from a specific surface area measured by the BET method of 10 to 60 nm, and (E) a basic compound;

a second composition that has a pH of 1 to 3, and includes at least (A) a cationic water-soluble polymer and (D) an acidic compound; and

a third composition that includes at least (B) an iron (III) compound and water.

9. The kit according to claim 8 , wherein the basic compound (E) is potassium hydroxide or ammonia.

10. The kit according to claim 8 , wherein the acidic compound (D) is an organic acid.

11. The kit according to claim 10 , wherein the organic acid is maleic acid or malonic acid.

12. The kit according to claim 8 , wherein the cationic water-soluble polymer (A) is a polyethylenimine.

13. The kit according to claim 8 , wherein the cationic water-soluble polymer (A) has a number average molecular weight of 200 to 1,000,000.

14. The kit according to claim 8 , wherein the iron (III) compound (B) is ferric nitrate.

15. A method of preparing the chemical mechanical polishing aqueous dispersion according to claim 1 , the method comprising mixing a first composition that has a pH of 8 to 11, and includes at least (C) colloidal silica having an average particle diameter calculated from a specific surface area measured by the BET method of 10 to 60 nm, and (E) a basic compound, a second composition that has a pH of 1 to 3, and includes at least (A) a cationic water-soluble polymer and (D) an acidic compound, and a third composition that includes at least (B) an iron (III) compound and water.