Compositions for the removal of post-etch and ashed photoresist residues and bulk photoresist
View Patent ↗The invention provides cleaning compositions for cleaning microelectronic substrates that are able to essentially completely clean such substrates and inhibit metal corrosion or produce essentially no corrosion of the metal elements of such substrates, and to do so at relatively short cleaning times and relatively low temperatures compared to the cleaning times required for prior art alkaline-containing cleaning compositions. The invention also provides method of using such cleaning compositions to clean microelectronic substrates without producing any significant corrosion of the metal elements of the microelectronic substrate. The cleaning compositions of this invention comprise (a) at least one organic solvent, (b) at least one unneutralized inorganic phosphorus-containing acid, and (c) water. The cleaning compositions of this invention optionally can have present in the compositions other components, such as for example surfactants, metal complexing or chelating agents, corrosion inhibitors, and the like. The cleaning compositions of this invention are characterized by an absence of organic amines, hydroxylamines or other strong bases such as ammonium bases and the like that would neutralize the inorganic phosphorus-containing acid component. The cleaning and residue removal compositions of this invention are especially suitable for cleaning microelectronic substrates containing aluminum, titanium, and tungsten.
1. A composition for cleaning microelectronic substrates consisting essentially of the following components:
(a) at last one water-soluble or water-miscible organic solvent,
(b) at least one unneutralized inorganic phosphorus-containing acid, and
(c) water,
and optionally
(d) at least one surfactant,
(e) at least one corrosion inhibitor, and
(f) at least one metal chelating or complexing agent;
wherein the composition is free of organic amines, hydroxylamines and strong bases that would neutralize the inorganic phosphorus-containing acid component and wherein the water-miscible organic solvent consists essentially of from about 35% to about 95% by weight of the composition and the weight ratio of the organic solvent component to the unneutralized inorganic phosphorus-containing acid component is in the range of from about 3:1 to about 40:1 and the water is present in the composition in an amount of from about 5% to about 10% based on the weight of the composition.
2. A composition according to claim 1 wherein the unneutralized inorganic phosphorus-containing acid comprises an acid selected from the group consisting of phosphorous (H 3 PO 3 ), hypophosphorous (H 3 PO 2 ) and phosphoric acids (H 3 PO 4 ).
3. A composition according to claim 2 wherein the water-soluble or water miscible organic solvent component is selected from the group consisting of N-methylpyrrolidinone, sulfolane, dimethylsulfoxide, diethylene glycol, propylene glycol, and dimethylacetamide.
4. A composition according to claim 2 wherein the unneutralized inorganic phosphorus-containing acid comprises phosphorous acid (H 3 PO 3 ).
5. A composition according to claim 3 wherein the unneutralized inorganic phosphorus-containing acid comprises hypophosphorous acid (H 3 PO 2 ).
6. A composition according to claim 1 wherein 1-hydroxyethane-1,1,-diphosphonic acid is present as a corrosion inhibitor.
7. A method of cleaning a microelectronic substrate, the substrate containing photoresist polymeric material, residues and a metal, the process comprising contacting the substrate with a cleaning composition for a time sufficient to clean the substrate, wherein the cleaning composition consisting essentially of the following components:
(a) at last one water-soluble or water-miscible organic solvent,
(b) at least one unneutralized inorganic phosphorus-containing acid, and
(c) water,
and optionally
(d) at least one surfactant,
(e) at least one corrosion inhibitor, and
(f) at least one metal chelating or complexing agent;
wherein the composition is free of organic amines, hydroxylamines and strong bases that would neutralize the inorganic phosphorus-containing acid component and wherein the water-miscible organic solvent consists essentially of from about 35% to about 95% by weight of the composition and the weight ratio of the organic solvent component to the unneutralized inorganic phosphorus-containing acid component is in the range of from about 3:1 to about 40:1 and the water is present in the composition in an amount of from about 5% to about 10% based on the weight of the composition.
8. A method according to claim 7 wherein the unneutralized inorganic phosphorus-containing acid comprises an acid selected from the group consisting of phosphorous (H 3 PO 3 ), hypophosphorous (H 3 PO 2 ) and phosphoric acids (H 3 PO 4 ).
9. A method according to claim 8 wherein the water-soluble or water miscible organic solvent component is selected from the group consisting of N-methylpyrrolidinone, sulfolane, dimethylsulfoxide, diethylene glycol, propylene glycol, and dimethylacetamide.
10. A method according to claim 8 wherein the unneutralized inorganic phosphorus-containing acid comprises phosphorous acid (H 3 PO 3 ).
11. A method according to claim 9 wherein the unneutralized inorganic phosphorus-containing acid comprises hypophosphorous acid (H 3 PO 2 ).
12. A method according to claim 7 wherein 1-hydroxyethane-1,1,-diphosphonic acid is present as a corrosion inhibitor.