Cleaning agent for semiconductor substrates and method for processing semiconductor substrate surface

1. A cleaning agent for a semiconductor substrate having a copper wiring film or a copper alloy wiring film, and a cobalt-containing film to be used in a post-process of a chemical mechanical polishing process, comprising (A) an organic acid represented by general formula (1), (B) piperazine, (C) a hydroxylamine derivative, and (D) an oxygen scavenger represented by general formula (6); and being an aqueous solution having a pH of 10 or higher:

wherein R 1 represents a carboxyl group, a 1,2,3-trihydroxypropyl group or a 3-oxo-1,2-dihydroxypropyl group;

wherein R 19 represents a hydrogen atom or a hydroxyl group, R 20 represents a hydrogen atom or a hydroxyl group, R 21 represents a hydrogen atom, a hydroxyl group, a carboxyl group or a propoxycarbonyl group, provided that at least one of R 19 to R 21 represents a hydroxyl group.

2. The cleaning agent according to claim 1 , wherein (A) the organic acid represented by general formula (1) is an organic acid selected from tartaric acid, gluconic acid. and galacturonic acid.

3. The cleaning agent according to claim 1 , wherein (A) the organic acid represented by general formula (1) is tartaric acid.

4. The cleaning agent according to claim 1 , wherein (C) the hydroxylamine derivative is a hydroxylamine derivative represented by general formula (7):

wherein R 22 represents an alkyl group having 1 to 6 carbon atoms, and R 23 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

5. The cleaning agent according to claim 1 , wherein (D) the oxygen scavenger represented by general formula (6) is an oxygen scavenger selected from pyrogallol, pyrocatechol, hydroquinone, gallic acid and propyl gallate.

6. The cleaning agent according to claim 1 , wherein (D) the oxygen scavenger represented by general formula (6) is pyrogallol.

7. The cleaning agent according to claim 1 , wherein the cleaning agent further comprises (E) an alkali compound.

8. The cleaning agent according to claim 7 , wherein (E) the alkali compound is a quaternary ammonium salt.

9. The cleaning agent according to claim 1 , wherein pH is 10 to 13.

10. The cleaning agent according to claim 1 , comprising 0.001 to 5% by weight of (A) the organic acid represented by general formula (1),0.0005 to 5% by weight of (B) piperazine, 0.01 to 25% by weight of (C) the hydroxylamine derivative, and 0.0001 to 1% by weight of (D) the oxygen scavenger represented by general formula (6).

11. The cleaning agent according to claim 10 , wherein the cleaning agent further comprises 0.1 to 5% by weight of (E) the alkali compound.

12. The cleaning agent according to claim 7 consisting of (A) the organic acid represented by general formula (1), (B) piperazine, (C) the hydroxylamine derivative, (D) the oxygen scavenger represented by general formula (6), (E) the alkali compound, and water.

13. The cleaning agent according to claim 1 , wherein the cobalt-containing film is a barrier metal of the copper wiring film or the copper alloy wiring film.

14. A processing method for the surface of a semiconductor substrate, having a copper wiring film or a copper alloy wiring film, and a cobalt-containing film, which comprises using the cleaning agent according to claim 1 .

15. The processing method according to claim 14 , wherein the cobalt-containing film is a barrier metal of the copper wiring film or the copper alloy wiring film.

16. The processing method according to claim 14 , wherein the semiconductor substrate is a substrate after chemical mechanical polishing.

17. The processing method according to claim 14 , wherein the processing method is a method for removing a coating film at the surface of the copper wiring film or the surface of the copper alloy wiring film, derived from benzotriazole or a derivative thereof.