Peroxide activated oxometalate based formulations for removal of etch residue
View Patent ↗Highly alkaline, aqueous formulations including (a) water, (b) at least one metal ion-free base at sufficient amounts to produce a final formulation alkaline pH, (c) from about 0.01% to about 5% by weight (expressed as % SiO 2 ) of at least one water-soluble metal ion-free silicate corrosion inhibitors; (d) from about 0.01% to about 10% by weight of at least one metal chelating agent, and (e) from more than 0 to about 2.0% by weight of at least one oxymetalate are provided in accordance with this invention. Such formulations are combined with a peroxide such that a peroxymetalate is formed to produce form a microelectronic cleaning composition. Used to remove contaminants and residue from microelectronic devices, such as microelectronic substrates.
1. An alkaline, aqueous formulation for combining with peroxide for cleaning a microelectronic device, the formulation comprising: (a) water, (b) at least one metal ion-free base at sufficient amounts to produce a final formulation having an alkaline pH (c) from about 0.01% to about 5% by weight (expressed as % SiO 2 ) of at least one water-soluble metal ion-free silicate corrosion inhibitor; (d) from about 0.01% to about 10% by weight of at least one metal chelating agent, and (e) from more than 0 to about 2.0% by weight of at least one oxometalate.
2. A formulation according to claim 1 wherein the oxometalate is an oxometalate of a metal selected from the group consisting of molybdenum (Mo), tungsten (W), vanadium (V), niobium (Nb), chromium (Cr) and tantalum (Ta).
3. A formulation according to claim 2 wherein the oxometalate is selected from the group consisting of mononuclear oxometalates, homopolynuclear oxometalates and heteropolynuclear oxometalates.
4. A formulation according to claim 2 wherein the alkaline pH of the formulation is from about pH 11 to about 13.4.
5. A formulation according to claim 2 wherein the metal ion-free base is an ammonium hydroxide, the metal ion-free silicate is a quaternary ammonium silicate, and the metal chelating agent is an aminocarboxylic acid.
6. A formulation according to claim 5 wherein the oxometalate is selected from the group consisting of ammonium molybdate ((NH 4 ) 2 MoO 4 ), ammonium tungstate ((NH 4 ) 2 WO 4 ), tungstic acid (H 2 WO 4 ), ammonium metavanadate (NH 4 VO 3 ), ammonium heptamolydbate ((NH 4 ) 6 Mo 7 O 24 ), ammonium metatungstate ((NH 4 ) 6 H 2 W 12 O 40 ), ammonium paratungstate ((NH 4 ) 10 H 2 W 12 O 42 ), tetramethylammonium decavanadate ((TMA) 4 H 2 V 10 O 28 ), tetramethylammonium decaniobate ((TMA) 6 Nb 10 O 28 ), ammonium dichromate ((NH 4 ) 2 Cr 2 O 7 ), ammonium phosphomolybdate ((NH 4 ) 3 PMo 12 O 40 , silicotungstic acid (H 4 SiW 12 O 40 ), phosphotungstic acid (H 3 PW 12 O 40 ), phosphomolybdic acid (H 3 PMo 12 O 40 ), silicomolybdic acid (H 4 SiMo 12 O 40 ), and molybdovanadophosphates (H 5 PMo 10 V 2 O 40 ).
7. A formulation according to claim 6 wherein the metal ion-free base is tetramethylammonium hydroxide, the metal ion-free silicate is tetramethylammonium silicate, the metal chelating agent is trans-1,2-cyclohexanediamine tetraacetic acid, and the oxometalate is selected from the group consisting of ammonium molybdate and silicotungstic acid.
8. A formulation according to claim 7 comprising 2.1% tetramethylammonium hydroxide, 0.14% tetramethylammonium silicate, 0.12% trans-1,2-cyclohexanediamine tetraacetic acid, and from about 0.01 to about 2% of the oxometalate, and the balance water to 100%.
9. A formulation according to claim 8 wherein the oxometalate is ammonium molybdate.
10. A formulation according to claim 8 wherein the oxomolybdate is silicotungstic acid.
11. An alkaline, aqueous cleaning composition for cleaning a microelectronic device, the cleaning composition comprising the formulation according to claim 1 admixed with at least one peroxide in a ratio of the formulation to peroxide from about 5:1 to about 40:1 and wherein the at least one peroxide is reactive with the oxometalate to form a peroxometalate.
12. An alkaline, aqueous cleaning composition for cleaning a microelectronic device, the cleaning composition comprising the formulation according to claim 2 admixed with at least one peroxide in a ratio of the formulation to peroxide from about 5:1 to about 40:1 and wherein the at least one peroxide is reactive with the oxometalate to form a peroxometalate.
13. An alkaline, aqueous cleaning composition for cleaning a microelectronic device, the cleaning composition comprising the formulation according to claim 7 admixed with at least one peroxide in a ratio of the formulation to peroxide from about 5:1 to about 40:1 and wherein the at least one peroxide is reactive with the oxometalate to form a peroxometalate.
14. An alkaline, aqueous cleaning composition according to claim 11 wherein the at least one peroxide comprises hydrogen peroxide.
15. An alkaline, aqueous cleaning composition according to claim 12 wherein the at least one peroxide comprises hydrogen peroxide.
16. An alkaline, aqueous cleaning composition according to claim 13 wherein the at least one peroxide comprises hydrogen peroxide.
17. A process for cleaning contaminants or residue from a microelectronic substrate comprising contacting the microelectronic substrate with a cleaning composition of claim 11 for a time and temperature sufficient to remove the contaminants or residue.
18. A process for cleaning contaminants or residue from a microelectronic substrate comprising contacting the microelectronic substrate with a cleaning composition of claim 12 for a time and temperature sufficient to remove the contaminants or residue.
19. A process for cleaning contaminants or residue from a microelectronic substrate comprising contacting the microelectronic substrate with a cleaning composition of claim 13 for a time and temperature sufficient to remove the contaminants or residue.
20. A process for cleaning contaminants or residue from a microelectronic substrate comprising contacting the microelectronic substrate with a cleaning composition of claim 16 for a time and temperature sufficient to remove the contaminants or residue.