Compositions for reducing metal etch rates using stripper solutions containing copper salts
Resist stripping agents, useful for fabricating circuits and/or forming electrodes on semiconductor devices for semiconductor integrated circuits with reduced metal etch rates, particularly copper etch rates, are provided with methods for their use. The preferred stripping agents contain low concentrations of a copper salt with or without an added amine to improve solubility of the salt. Further provided are integrated circuit devices and electronic interconnect structures prepared according to these methods.
1. A composition for removing a resist from a metal-containing substrate, comprising dimethyl sulfoxide (DMSO), a quaternary ammonium hydroxide, an alkanolamine, and a copper metal salt.
2. The composition of claim 1 wherein said composition comprises from about 0.001 wt. % to about 0.10 wt. % copper salt.
3. The composition of claim 2 wherein said composition comprises from about 0.005 wt. % to about 0.075 wt. % copper salt.
4. The composition of claim 3 wherein said composition comprises about 0.025 wt. % copper salt.
5. The composition of claim 1 wherein said composition includes a monomeric or polymeric amine effective for improving the solubility of the copper salt in the solution.
6. The composition of claim 1 wherein said composition further includes a secondary solvent.
7. The composition of claim 6 wherein said secondary solvent is a glycol ether.
8. The composition of claim 7 wherein said glycol ether is 3-methyl-3-methoxybutanol.
9. The composition of claim 1 wherein said copper salt is CuCl or Cu(NO 3 ) 2 .
10. The composition of claim 1 wherein said alkanolamine has at least two carbon atoms, at least one amino substituent, and at least one hydroxyl substituent, with the amino and the hydroxyl substituents being attached to different carbon atoms.
11. The composition of claim 1 wherein said quaternary ammonium hydroxide is tetramethylammonium hydroxide.
12. The composition of claim 1 wherein said alkanolamine is monoethanolamine.
13. The composition of claim 10 wherein said alkanolamine has at least two carbon atoms, at least one amino substituent, and exactly one hydroxyl substituent, with the amino and the hydroxyl substituents being attached to different carbon atoms.
14. The composition of claim 10 wherein said alkanolamine is selected from the group consisting of monoethanolamine (MEA) and aminoethylethanolamine (AEEA).
15. The composition of claim 1 wherein said alkanolamine is aminoethylethanolamine.