Oxidizing aqueous cleaner for the removal of post-etch residues
View Patent ↗An oxidizing aqueous cleaning composition and process for cleaning post-plasma etch residue and/or hardmask material from a microelectronic device having said residue thereon. The oxidizing aqueous cleaning composition includes at least one oxidizing agent, at least one oxidizing agent stabilizer comprising an amine species selected from the group consisting of primary amines, secondary amines, tertiary amines and amine-N-oxides, optionally at least one co-solvent, optionally at least one metal-chelating agent, optionally at least one buffering species, and water. The composition achieves highly efficacious cleaning of the residue material from the microelectronic device while simultaneously not damaging the interlevel dielectric and metal interconnect material also present thereon.
1. An aqueous cleaning composition, comprising at least one oxidizing agent, at least one amine-N-oxide, optionally at least one organic co-solvent, at least one metal-chelating agent, optionally at least one buffering species, and water, wherein the pH of the cleaning composition is about 3 to 9, and wherein the at least one metal-chelating agent comprises ethylenediaminetetraacetic acid (EDTA), 1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid (CDTA), or combinations thereof.
2. The aqueous cleaning composition of claim 1 , wherein the at least one oxidizing agent comprises hydrogen peroxide.
3. The aqueous cleaning composition of claim 1 , wherein the amine-N-oxide comprises a species selected from the group consisting of N-methylmorpholine-N-oxide (NMMO), trimethylamine-N-oxide, triethylamine-N-oxide, pyridine-N-oxide, N-ethylmorpholine-N-oxide, N-methylpyrrolidine-N-oxide, N-ethylpyrrolidine-N-oxide, and combinations thereof.
4. The aqueous cleaning composition of claim 1 , comprising N-methylmorpholine-N-oxide.
5. The aqueous cleaning composition of claim 1 , comprising at least one organic co-solvent, wherein said organic co-solvent comprises a species selected from the group consisting of ethylene glycol, propylene glycol (PG), neopentyl glycol, 1,3-propanediol, diethyleneglycol, dipropyleneglycol, glycerol, formamide, acetamide, higher amides, N-methylpyrrolidone (NMP), N,N-dimethylformamide, N,N-dimethylacetamide, sulfolane, dimethylsulfoxide (DMSO), γ-butyrolactone, propylene carbonate, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether (i.e., butyl carbitol), triethylene glycol monobutyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, ethylene glycol phenyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether (DPGPE), tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, and combinations thereof.
6. The aqueous cleaning composition of claim 1 , comprising diethylene glycol monobutyl ether.
7. The aqueous cleaning composition of claim 1 , comprising the at least one buffering species, wherein the buffering species comprises a tetralkylammonium cation compound and an acid anion compound, wherein the tetralkylammonium cation compound includes a tetralkylammonium cation represented by the formula [NR 1 R 2 R 3 R 4 ] + , where R 1 , R 2 , R 3 and R 4 may be the same as or different from one another and are selected from the group consisting of straight-chained C 1 -C 6 alkyls, branched C 1 -C 6 alkyls, substituted C 6 -C 10 aryls, unsubstituted C 6 -C 10 aryls, and combinations thereof, and wherein the acid anion compound is selected from the group consisting of lactic acid, maleic acid, ascorbic acid, malic acid, benzoic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, mandelic acid, maleic anhydride, citric acid, phthalic acid, boric acid other aliphatic and aromatic carboxylic acids, and combinations of the foregoing acids.
8. The aqueous cleaning composition of claim 7 , comprising a tetralkylammonium salt of citric acid or a tetralkylammonium salt of boric acid.
9. The aqueous cleaning composition of claim 1 , comprising at least one organic co-solvent, at least one metal chelating agent, and at least one buffering species, wherein the aqueous cleaning composition comprises hydrogen peroxide, at least one amine-N-oxide, diethylene glycol butyl ether, 1,2,4-triazole, tetramethylammonium hydroxide and citric acid.
10. The aqueous cleaning composition of claim 1 , comprising at least one organic co-solvent, at least one metal chelating agent, and at least one buffering species, wherein the aqueous cleaning composition comprises hydrogen peroxide, at least one amine-N-oxide, diethylene glycol butyl ether, 1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid, tetramethylammonium hydroxide and boric acid.
11. The aqueous cleaning composition of claim 1 , having a pH in a range from about 6 to about 8.
12. A method of removing post-plasma etch residue and/or hardmask material from a microelectronic device having said residue and/or hardmask thereon, said method comprising contacting the microelectronic device with an aqueous cleaning composition for sufficient time to at least partially clean said residue and/or hardmask from the microelectronic device, wherein the aqueous cleaning composition includes at least one oxidizing agent, at least one amine-N-oxide, optionally at least one organic co-solvent, at least one metal-chelating agent, optionally at least one buffering species, and water, wherein the pH of the cleaning composition is about 3 to 9, and wherein the at least one metal-chelating agent comprises ethylenediaminetetraacetic acid (EDTA), 1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid (CDTA), or combinations thereof.
13. The method of claim 12 , wherein the at least one oxidizing agent comprises hydrogen peroxide; and
wherein the at least one amine-N-oxide comprises an amine species selected from the group consisting of N-methylmorpholine-N-oxide (NMMO), trimethylamine-N-oxide, triethylamine-N-oxide, pyridine-N-oxide, N-ethylmorpholine-N-oxide, N-methylpyrrolidine-N-oxide, N-ethylpyrrolidine-N-oxide, and combinations thereof.
14. The method of claim 12 , wherein the aqueous cleaning composition comprises at least one organic co-solvent selected from the group consisting of ethylene glycol, propylene glycol (PG), neopentyl glycol, 1,3-propanediol, diethyleneglycol, dipropyleneglycol, glycerol, formamide, acetamide, higher amides, N-methylpyrrolidone (NMP), N,N-dimethylformamide, N,N-dimethylacetamide, sulfolane, dimethylsulfoxide (DMSO), γ-butyrolactone, propylene carbonate, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether (i.e., butyl carbitol), triethylene glycol monobutyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, ethylene glycol phenyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether (DPGPE), tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, and combinations thereof.
15. The method of claim 12 , wherein said composition has a pH in a range of from about 6 to about 8.
16. The method of claim 12 , wherein the contacting comprises a process selected from the group consisting of: spraying the aqueous composition on a surface of the microelectronic device; dipping the microelectronic device in a sufficient volume of aqueous composition; contacting a surface of the microelectronic device with another material that is saturated with the aqueous composition; and contacting the microelectronic device with a circulating aqueous composition.
17. The method of claim 12 , further comprising rinsing the microelectronic device with deionized water following contact with the aqueous composition.
18. The method of claim 12 , further comprising contacting the microelectronic device with dilute hydrofluoric acid.