Metal- polishing liquid and chemical-mechanical polishing method using the same

Abstract

A metal-polishing liquid contains at least one heterocyclic compound having from one to three nitrogen atom as heteroatoms in a molecule; and colloidal silica having a surface partially covered with aluminum. A chemical-mechanical polishing method contains processes of supplying the metal-polishing liquid to a polishing pad on a polishing platen; rotating the polishing platen; relatively moving the polishing pad while the polishing pad is contacted with a surface to be polished of an object to be polished; and polishing the surface to be polished of the object to be polished.

Description

Claims

1. A metal-polishing liquid comprising: at least one heterocyclic compound having from one to three nitrogen atom as heteroatoms in a molecule, andcolloidal silica having a surface partially covered with aluminum.

2. The metal-polishing liquid according to claim 1, wherein the heterocyclic compound has at least one carboxylic group.

3. The metal-polishing liquid according to claim 1, wherein the heterocyclic compound has a plurality of carboxylic groups.

4. The metal-polishing liquid according to claim 1, wherein the pH thereof is in a range of from 5 to 8.

5. The metal-polishing liquid according to claim 1, wherein the heterocyclic compound is 1,2,3-triazole, 1,2,4-triazole or a derivative thereof.

6. The metal-polishing liquid according to claim 1, further comprising at least one organic acid.

7. The metal-polishing liquid according to claim 6, wherein the organic acid is an amino acid.

8. The metal-polishing liquid according to claim 1, wherein an average value of the volume equivalent diameter of the colloidal silica is in the range of from 10 nm to 60 nm.

9. The metal-polishing liquid according to claim 1, wherein the surface atom substitution ratio (number of introduced aluminum atoms/number of surface silicon atoms) is in the range of from 0.01% to 10%.

10. The metal-polishing liquid according to claim 1, wherein the surface atom substitution ratio (number of introduced aluminum atoms/number of surface silicon atoms) is particularly in the range of from 0.1% to 5%.

11. The metal-polishing liquid according to claim 1, wherein a ratio of a content of the heterocyclic compound with respect to a content of the colloidal silica (heterocyclic compound/colloidal silica) is in the range of from 0.00002 to 1000.

12. A chemical-mechanical polishing method comprising: supplying the metal-polishing liquid according to claim 1 to a polishing pad on a polishing platen;rotating the polishing platen;relatively moving the polishing pad while the polishing pad is contacted with a surface to be polished of an object to be polished to polish the surface to be polished of the object to be polished.

13. The chemical-mechanical polishing method according to claim 12, wherein the polishing object is a substrate comprising wiring comprising copper or a copper alloy.

14. The chemical-mechanical polishing method according to claim 13, wherein the copper alloy contains silver in the range of from 0.00001 to 0.1% by mass.

15. The chemical-mechanical polishing method according to claim 12, wherein object to be polished has an insulating film provided on wiring comprising copper or a copper alloy, and a barrier layer containing Ta or TaN is provided between the wiring and the insulating film.

16. The chemical-mechanical polishing method according to claim 12, wherein the contact pressure between the surface to be polished and the polishing pad is in the range of form 6,500 to 14,000 Pa.

17. The chemical-mechanical polishing method according to claim 12, wherein the rotation speed of the polishing platen is in the range of from 50 to 200 rpm.

18. The chemical-mechanical polishing method according to claim 14, wherein an amount of supplying the metal-polishing liquid to a polishing pad is in a range of from 50 to 500 ml/min.