Cleaning solution formulations for substrates
View Patent ↗Presented is a cleaning solution according to one embodiment of the present invention that includes a corrosion inhibitor, a solubilizing agent, an oxygen scavenger, and a complexing agent also capable as a pH adjustor. Another embodiment of the present invention includes cleaning solutions that include a pH adjustor, an optional complexing agent, and a corrosion inhibitor. The cleaning solutions may have a solubilizing agent optionally present, may have a surfactant optionally present, and may have a dielectric etchant optionally present.
1. An aqueous cleaning solution for removing metal contaminants from a dielectric structure with electrolessly deposited cobalt or cobalt alloy caps after electrolessly depositing the cobalt or cobalt alloy caps over metal lines in the dielectric structure, comprising:
a pH adjustor;
a complexing agent comprising phytic acid;
a corrosion inhibitor capable so as to protect electrolessly deposited cobalt or cobalt alloy caps on metal lines over the dielectric structure; and
one or more of:
a solubilizing agent,
a dielectric etchant, and
a surfactant; and
wherein the aqueous cleaning solution is capable so as to remove metal ions from the dielectric structure, wherein:
the pH adjustor has a concentration of less than 0.1 M and includes at least one of a sulphuric acid, sulfonic acid, methanesulfonic acid, benzene sulfonic acid, triflic acid, hypophosphorous acid, oxalic acid, halogenated carboxylic acids, trifluoroacetic acid, acetylenedicarboxylic acid, squaric acid, dihydroxyfumaric acid, maleic acid, or mixtures thereof;
the complexing agent has a concentration from 0.1 to 200 mM;
the corrosion inhibitor has a concentration from 0.1 to 50 mM and comprises at least one of a triazole, benzotriazole, methyl-benzotriazole, 5-methyl-benzotriazole, carboxy-benzotriazole, hydroxybenzotriazole, mercaptobenzothiazole, polyvinylpyrrolidone, polyvinylalcohol, polyamine, polyimine, polyalkylimine, polyethylenimine, long chain alkylamine, tetrazole, phosphate, inorganic phosphate, alkylphosphate, metaphosphate, phosphite, phosphonate, fluoroalkylphosphate, silicate, alkylphosphonate, fluoroalkylphosphonate, alkoxysilane, nitrite, bicyclohexylammonium nitrite, or combinations thereof;
the solubilizing agent is present at a concentration less than 200 mL/L and comprises one or more of a primary alcohol, secondary alcohol, tertiary alcohol, polyol, ethylene glycol, propylene glycol, 2-n-butoxyethanol, dimethylsulfoxide, propylenecarbonate, or combinations thereof;
the dielectric etchant is present at a concentration from 1 to 100 mM and comprises one or more of a hydrogen fluoride, hydrogen tetrafluoroborate, hydrogen hexafluorosilicate, non-alkali metal alt of fluoride, tetrafluoroborate, hexafluorosilicate, or mixtures thereof;
the surfactant is present at a concentration of less than 2000 ppm and comprises at least one of anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, or combinations thereof; and
the aqueous cleaning solution has a pH less than or equal to 3.
2. An aqueous cleaning solution for removing metal contaminants from a dielectric structure with electrolessly deposited cobalt or cobalt alloy caps after electrolessly depositing the cobalt or cobalt alloy caps over metal lines in the dielectric structure, comprising:
a pH adjustor;
a complexing agent comprising phytic acid;
a corrosion inhibitor capable so as to protect electrolessly deposited cobalt or cobalt alloy caps on metal lines over the dielectric structure; and
one or more of:
a solubilizing agent, wherein the solubilizing agent comprises one or more of dimethylsulfoxide, ethylene glycol, propylene glycol, 2-n-butoxyethanol, or isopropyl alcohol
a dielectric etchant, and
a surfactant; and
wherein the aqueous cleaning solution is capable so as to remove metal ions from the dielectric structure.
3. An aqueous cleaning solution for removing metal contaminants from a dielectric structure with electrolessly deposited cobalt or cobalt alloy caps after electrolessly depositing the cobalt or cobalt alloy caps over metal lines in the dielectric structure, comprising:
a pH adjustor comprising hypophosphorous acid, squaric acid, dihydroxyfumaric acid, or mixtures thereof;
a complexing agent comprising phytic acid;
a corrosion inhibitor capable so as to protect an electrolessly deposited cobalt or cobalt alloy caps on a metal lines over the dielectric structure; and
one or more of:
a solubilizing agent,
a dielectric etchant, and
a surfactant; and
wherein the aqueous cleaning solution is capable so as to remove metal ions from the dielectric structure.
4. The aqueous cleaning solution of claim 3 , wherein:
the complexing agent further comprises at least one of carboxylic acids, hydroxycarboxylic acids, citric acid, oxalic acid, phosphonic acid, hydroxyethylidene diphosphonic acid, or mixtures thereof;
the corrosion inhibitor comprises at least one of a triazole, benzotriazole, methyl-benzotriazole, 5-methyl-benzotriazole, carboxy-benzotriazole, hydroxybenzotriazole, mercaptobenzothiazole, polyvinylpyrrolidone, polyvinylalcohol, polyamine, polyimine, polyalkylimine, polyethylenimine, long chain alkylamine, tetrazole, phosphate, inorganic phosphate, alkylphosphate, metaphosphate, phosphite, phosphonate, fluoroalkylphosphate, silicate, alkylphosphonate, fluoroalkylphosphonate, alkoxysilane, nitrite, bicyclohexylammonium nitrite, or combinations thereof;
the solubilizing agent comprises one or more of a dimethylsulfoxide, ethylene glycol, propylene glycol, 2-n-butoxyethanol, or isopropyl alcohol;
the dielectric etchant comprises one or more of a hydrogen fluoride, hydrogen tetrafluoroborate, hydrogen hexafluorosilicate, non-alkali metal salts of fluoride, tetrafluoroborate, hexafluorosilicate, or mixtures thereof;
the surfactant comprises at least one of anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, or combinations thereof; and
the aqueous cleaning solution has a pH less than or equal to 3.
5. The aqueous cleaning solution of claim 3 , wherein:
the pH adjustor has a concentration of less than 0.1 M;
the complexing agent has a concentration from 0.1 to 200 mM and further comprises at least one of a carboxylic acid, hydroxycarboxylic acid, citric acid, oxalic acid, phosphonic acid, hydroxyethylidene diphosphonic acid, or combinations thereof;
the corrosion inhibitor has a concentration from 0.1 to 50 mM and comprises at least one of a triazole, benzotriazole, methyl-benzotriazole, 5-methyl-benzotriazole, carboxy-benzotriazole, hydroxybenzotriazole, mercaptobenzothiazole, polyvinylpyrrolidone, polyvinylalcohol, polyamine, polyimine, polyalkylimine, polyethylenimine, long chain alkylamine, tetrazole, phosphate, inorganic phosphate, alkylphosphate, metaphosphate, phosphite, phosphonate, fluoroalkylphosphate, silicate, alkylphosphonate, fluoroalkylphosphonate, alkoxysilane, nitrite, bicyclohexylammonium nitrite, or combinations thereof;
the solubilizing agent is present at a concentration less than 200 mL/L and comprises one or more of a primary alcohol, secondary alcohol, tertiary alcohol, polyol, ethylene glycol, propylene glycol, 2-n-butoxyethanol, dimethylsulfoxide, propylenecarbonate, or combinations thereof;
the dielectric etchant is present at a concentration from 1 to 100 mM and comprises one or more of a hydrogen fluoride, hydrogen tetrafluoroborate, hydrogen hexafluorosilicate, non-alkali metal salts of fluoride, tetrafluoroborate, hexafluorosilicate, or mixtures thereof;
the surfactant is present at a concentration of less than 2000 ppm and comprises at least one of anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, or combinations thereof; and
the aqueous cleaning solution has a pH less than or equal to 3.
6. The aqueous cleaning solution of claim 3 , wherein:
the complexing agent further comprises at least one of carboxylic acids, hydroxycarboxylic acids, citric acid, oxalic acid, phosphonic acid, hydroxyethylidene diphosphonic acid, or mixtures thereof.
7. The aqueous cleaning solution of claim 3 , wherein:
the corrosion inhibitor comprises at least one of a triazole, benzotriazole, methyl-benzotriazole, 5-methyl-benzotriazole, carboxy-benzotriazole, hydroxybenzotriazole, mercaptobenzothiazole, polyvinylpyrrolidone, polyvinylalcohol, polyamine, polyimine, polyalkylimine, polyethylenimine, long chain alkylamine, tetrazole, phosphate, inorganic phosphate, alkylphosphate, metaphosphate, phosphite, phosphonate, fluoroalkylphosphate, silicate, alkylphosphonate, fluoroalkylphosphonate, alkoxysilane, nitrite, bicyclohexylammonium nitrite, or combinations thereof.
8. The aqueous cleaning solution of claim 3 , wherein:
the dielectric etchant comprises one or more of a hydrogen fluoride, hydrogen tetrafluoroborate, hydrogen hexafluorosilicate, non-alkali metal salts of fluoride, tetrafluoroborate, hexafluorosilicate, or mixtures thereof.
9. The aqueous cleaning solution of claim 3 , wherein:
the solubilizing agent comprises one or more of dimethylsulfoxide, ethylene glycol, propylene glycol, 2-n-butoxyethanol, or isopropyl alcohol.
10. The aqueous cleaning solution of claim 3 , wherein:
the pH adjustor has a concentration of between 0 to 0.1 M;
the complexing agent has a concentration from 0.1 to 200 mM;
the corrosion inhibitor has a concentration from 0.1 to 50 mM;
the solubilizing agent has a concentration from 0 to 200 mL/L;
the dielectric etchant has a concentration from 1 to 100 mM;
the surfactant has a concentration from 0 to 2000 ppm; and
the aqueous cleaning solution has a pH less than or equal to 3.
11. An aqueous cleaning solution for removing metal contaminants from a dielectric structure with electrolessly deposited cobalt or cobalt alloy caps after electrolessly depositing the cobalt or cobalt alloy caps over metal lines in the dielectric structure, comprising:
a pH adjustor;
a complexing agent comprising phytic acid;
a corrosion inhibitor capable so as to protect electrolessly deposited cobalt or cobalt alloy caps on metal lines over the dielectric structure; and
one or more of:
a solubilizing agent, wherein:
the pH adjustor has a concentration of less than 0.1 M and comprises hypophosphorous acid, squaric acid, dihydroxyfumaric acid, or mixtures thereof;
the complexing agent has a concentration from 0.1 to 200 mM;
the dielectric etchant is present at a concentration from 1 to 100 mM and comprises one or more of a hydrogen tetrafluoroborate, hydrogen hexafluorosilicate, tetrafluoroborate, hexafluorosilicate, and mixtures thereof; and
the aqueous cleaning solution has a pH less than or equal to 3.