Aqueous acidic formulations for copper oxide etch residue removal and prevention of copper electrodeposition
View Patent ↗A highly aqueous acidic cleaning composition for copper oxide etch removal from Cu-dual damascene microelectronic structures and wherein that composition prevents or substantially eliminates copper redeposition on the Cu-dual damascene microelectronic structure.
1. An aqueous, acidic cleaning composition for cleaning Cu-dual damascene microelectronic structures, the composition comprising a formulation of:
(a) from about 68.45% to about 98.95% water;
(b) from about 0.3% to about 8% by weight of at least one alkanolamine or aminophenol;
(c) from about 0.1% to about 2% of at least one metal chelating agent;
(d) from about 0.05% to about 1.6% of at least one tetraalkylammonium fluoride;
(e) from about 0.1% to about 5% of hydrogen fluoride; and
(f) from greater than 0% to about 15% of at least one non-ionic surfactant that contains ethylene oxide chains or ethylene oxide/ethylene glycol chains;
wherein the percentages are weight percent based on the total weight of the formulation and the composition has a pH of from about 4 to about 5.5.
2. An aqueous, acidic cleaning composition of claim 1 comprising a formulation of:
(a) from about 69.46% to about 89.5% water;
(b) from about 3% to about 8% by weight of at least one alkanolamine or aminophenol;
(c) from about 1% to about 2% of at least one metal chelating agent;
(d) from about 0.5% to about 1.6% of at least one tetraalkylammonium fluoride;
(e) from about 1% to about 5% of hydrogen fluoride; and
(f) from about 5% to about 15% of at least one non-ionic surfactant that contains ethylene oxide chains or ethylene oxide/ethylene glycol chains.
3. An aqueous, acidic cleaning composition of claim 1 comprising a formulation of:
(a) from about 96.86% to about 98.95% water;
(b) from about 0.3% to about 0.8% by weight of at least one alkanolamine or aminophenol;
(c) from about 0.1% to about 0.2% of at least one metal chelating agent;
(d) from about 0.05% to about 0.16% of at least one tetraalkylammonium fluoride;
(e) from about 0.1% to about 0.5% of hydrogen fluoride; and
(f) from greater than 0% to about 1.5% of at least one non-ionic surfactant that contains ethylene oxide chains or ethylene oxide/ethylene glycol chains.
4. An aqueous, acidic cleaning composition of claim 3 wherein the cleaning composition additionally comprises a reducing agent in the formulation in an amount of from about 0.5% to about 20% by weight based on the total weight of the other components in the formulation.
5. An aqueous, acidic cleaning composition of claim 1 wherein the formulation comprises: water, monoethanolamine, 1,2-cyclohexanediamine tetraacetic acid, tetramethylammonium fluoride, HF and a surfactant of the formula
6. An aqueous, acidic cleaning composition of claim 2 wherein the formulation comprises: water, monoethanolamine, 1,2-cyclohexanediamine tetraacetic acid, tetramethylammonium fluoride, HF and a surfactant of the formula
7. An aqueous, acidic cleaning composition of claim 3 wherein the formulation comprises: water, monoethanolamine, 1,2-cyclohexanediamine tetraacetic acid, tetramethylammonium fluoride, HF, and a polyoxyethylene substituted alkynol surfactant.
8. An aqueous, acidic cleaning composition of claim 3 wherein the formulation further comprises a reducing agent comprising ascorbic acid.
9. An aqueous, acidic cleaning composition of claim 5 wherein the formulation comprises:
(a) about 78% water;
(b) about 3.85% monoethanolamine;
(c) about 1.87% 1,2-cyclohexanediamine tetraacetic acid;
(d) about 0.77% tetramethylammonium fluoride;
(e) about 1.2% HF; and
(f) about 14.3% a polyoxyethylene substituted alkynol surfactant.
10. An aqueous, acidic cleaning composition of claim 7 wherein the formulation comprises:
(a) about 98% water;
(b) about 0.35% monoethanolamine;
(c) about 0.17% 1,2-cyclohexanediamine tetraacetic acid;
(d) about 0.07% tetramethylammonium fluoride;
(e) about 0.11% HF; and
(f) about 1.3% a polyoxyethylene substituted alkynol surfactant.
11. An aqueous, acidic cleaning composition of claim 10 wherein the formulation additionally comprises ascorbic acid in an amount of from about 2% to about 6% by weight based on the total weight of the other components of the formulation.
12. A method of forming a composition of claim 3 comprising adding about 10 parts by weight of water to 1 part by weight of a formulation comprising:
(a) from about 69.46% to about 89.5% water;
(b) from about 3% to about 8% by weight of at least one alkanolamine or aminophenol;
(c) from about 1% to about 2% of at least one metal chelating agent;
(d) from about 0.5% to about 1.6% of at least one tetraalkylammonium fluoride;
(e) from about 1% to about 5% of hydrogen fluoride; and
(f) from about 5% to about 15% of at least one non-ionic surfactant that contains ethylene oxide chains or ethylene oxide/ethylene glycol chains, wherein the percentages are by weight based on the total weight of the formulation.
13. A method of forming a composition of claim 4 comprising:
(1) adding about 10 parts by weight of water to 1 part by weight of a formulation comprising:
(a) from about 69.46% to about 89.5% water;
(b) from about 3% to about 8% by weight of at least one alkanolamine or aminophenol;
(c) from about 1% to about 2% of at least one metal chelating agent;
(d) from about 0.5% to about 1.6% of at least one tetraalkylammonium fluoride;
(e) from about 1% to about 5% of hydrogen fluoride; and
(f) from about 5% to about 15% of at least one non-ionic surfactant that contains ethylene oxide chains or ethylene oxide/ethylene glycol chains, wherein the percentages are by weight based on the total weight of the formulation, and
(2) adding to said resulting mixture a reducing agent in an amount of from about 0.5% to about 20% by weight based on the total weight of the other components in the resulting mixture.