Composition and method for recycling semiconductor wafers having low-k dielectric materials thereon
View Patent ↗A removal composition and process for removing low-k dielectric material, etch stop material, and/or metal stack material from a rejected microelectronic device structure having same thereon. The removal composition includes hydrofluoric acid. The composition achieves at least partial removal of the material(s) from the surface of the microelectronic device structure having same thereon, for recycling and/or reuse of said structure, without damage to the underlying polysilicon or bare silicon layer employed in the semiconductor architecture.
1. A removal composition, comprising hydrofluoric acid, at least one organic solvent, at least one chelating agent, and water,
wherein the composition comprises less than 1 wt. % amine species and greater than 10 wt % hydrofluoric acid, based on the total weight of said composition, and wherein said chelating agent comprises a species selected from the group consisting of acac, hfac, tfac, bis(trimethylsilylamide) tetramer, glycine, alanine, succinic acid, malonic acid, nitrilotriacetic acid, iminodiacetic acid, EDTA, CDTA, and combinations thereof.
2. The removal composition of claim 1 , further comprising at least one additional species selected from the group consisting of at least one oxidizing agent, at least one additional acid, at least one surfactant, and combinations thereof.
3. The removal composition of claim 1 , wherein the at least one organic solvent comprises a species selected from the group consisting of alcohols, ethers, pyrrolidinones, glycols, sulfur-containing solvents, glycol ethers, carboxylic acids, and combinations thereof.
4. The removal composition of claim 1 , further comprising material dissolved therein, wherein said material is selected from the group consisting of low-k dielectric material, metal stack material, and combinations thereof.
5. The removal composition of claim 1 , wherein the composition comprises HF, water, tetramethylene sulfone, and at least one glycol ether.
6. The removal composition of claim 1 , wherein the amount of water is less than 80 wt. %, based on the total weight of the composition.
7. The removal composition of claim 1 , wherein said chelating agent comprises a species selected from the group consisting of glycine, alanine, nitrilotriacetic acid, iminodiacetic acid, EDTA, CDTA, and combinations thereof.
8. The removal composition of claim 2 , comprising oxidizing agent, wherein said oxidizing agent comprises a species selected from the group consisting of hydrogen peroxide, oxone, oxone tetrabutylammonium salt, ferric nitrate, potassium iodate, potassium permanganate, nitric acid, ammonium chlorite, ammonium chlorate, ammonium iodate, ammonium perborate, ammonium perchlorate, ammonium periodate, ammonium persulfate, sodium persulfate, potassium persulfate, tetramethylammonium chlorite, tetramethylammonium chlorate, tetramethylammonium iodate, tetramethylammonium perborate, tetramethylammonium perchlorate, tetramethylammonium periodate, tetramethylammonium persulfate, urea hydrogen peroxide, peracetic acid, and combinations thereof.
9. The removal composition of claim 2 , wherein said composition comprises HF, water, sulfolane, CDTA, hydrogen peroxide, and diethylene glycol butyl ether.
10. The removal composition of claim 1 , wherein the pH of a 20:1 dilution of the removal composition in water is in a range from about 2.5 to about 4.5.
11. A kit comprising, in one or more containers, one or more of the following reagents for forming a removal composition, wherein said removal composition comprises hydrofluoric acid, at least one organic solvent, and at least one chelating agent, wherein the composition comprises less than 1 wt. % amine species and greater than 10 wt % hydrofluoric acid, based on the total weight of said composition, wherein said chelating agent comprises a species selected from the group consisting of acac, hfac, tfac, bis(trimethylsilylamide) tetramer, glycine, alanine, succinic acid, malonic acid, nitrilotriacetic acid, iminodiacetic acid, EDTA, CDTA, and combinations thereof, and wherein the kit is adapted to form a removal composition suitable for removing material selected from the group consisting of low-k dielectric material, etch stop material, metal stack material, and combinations thereof from a microel ectronic device having said material thereon.
12. A method of removing material from a microelectronic device having said material thereon, said method comprising contacting a microelectronic device structure with a removal composition for sufficient time to at least partially remove material selected from the group consisting of low-k dielectric material, etch stop material, metal stack material, and combinations thereof, from the microelectronic device structure, wherein the removal composition includes hydrofluoric acid, at least one organic solvent, at least one chelating agent, and water, wherein the composition comprises less than 1 wt. % amine species and greater than 10 wt % hydrofluoric acid, based on the total weight of said composition, and wherein said chelating agent comprises a species selected from the group consisting of acac, hfac, tfac, bis(trimethylsilylamide) tetramer, glycine, alanine, succinic acid, malonic acid, nitrilotriacetic acid, iminodiacetic acid, EDTA, CDTA, and combinations thereof.
13. The method of claim 12 , wherein said contacting comprises conditions selected from the group consisting of time of from about 30 seconds to about 60 minutes; temperature in a range of from about 20° C. to about 90° C.; and combinations thereof.
14. The method of claim 12 , further comprising at least one additional species selected from the group consisting of at least one oxidizing agent, at least one additional acid, at least one surfactant, and combinations thereof.
15. The method of claim 12 , wherein the at least one organic solvent comprises a compound selected from the group consisting of methanol, ethanol, isopropanol, butanol, diols, triols, 2,2,3,3,4,4,5,5-octafluoro-1-pentanol, 1H,1H,9H-perfluoro-1-nonanol, perfluoroheptanoic acid, 1H,1H,7H-dodecafluoro-1-heptanol, perfluoropentanoic acid, 1H,1H,8H,8H-dodecafluoro-1,8-octanediol, 2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol, 5H-perfluoropentanoic acid, n-butyl heptafluorobutyrate, tetrahydrofuran (THF), N-methylpyrrolidinone (NMP), cyclohexylpyrrolidinone, N-otylpyrrolidinone, N-phenylpyrrolidinone, methyl formate, dimethyl formamide (DMF), dimethylsulfoxide (DMSO), tetramethylene sulfone (sulfolane), diethyl ether, phenoxy-2-propanol (PPh), propriopheneone, ethyl lactate, ethyl acetate, ethyl benzoate, acetonitrile, acetone, ethylene glycol, propylene glycol, dioxane, butyryl lactone, butylene carbonate, ethylene carbonate, propylene carbonate, dipropylene glycol, 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, 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, dipropylene glycol dimethyl ether, dipropylene glycol ethyl 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.
16. The method of claim 12 , further comprising material dissolved therein, wherein said material is selected from the group consisting of low-k dielectric material, metal stack material, and combinations thereof.
17. The method of claim 16 , wherein the low-k dielectric material comprises dielectric material selected from the group consisting of silicon-containing organic polymers, silicon-containing hybrid organic materials, silicon-containing hybrid inorganic materials, organosilicate glass (OSG), TEOS, fluorinated silicate glass (FSG), silicon nitride, and carbon-doped oxide (CDO) glass;
wherein the etch stop material comprise a material selected from the group consisting of silicon carbide (SiC), silicon carbon nitride (SiCN), silicon carbon oxide (SiCO), silicon oxynitride (SiON), copper, silicon germanium (SiGe), SiGeB, SiGeC, AlAs, InGaP, InP, InGaAs, and combinations thereof; and
wherein the metal stack material comprises a material selected from the group consisting of tantalum, tantalum nitride, titanium nitride, titanium, nickel, cobalt, tungsten, and silicides thereof; copper; aluminum; Al/Cu; alloys of Al; alloys of Cu; hafnium oxides; hafnium oxysilicates; zirconium oxides; lanthanide oxides; titanates; and combinations thereof.
18. The method of claim 12 , wherein said chelating agent comprises a species selected from the group consisting of glycine, alanine, nitrilotriacetic acid, iminodiacetic acid, EDTA, CDTA, and combinations thereof.
19. The method of claim 14 , comprising oxidizing agent, wherein said oxidizing agent comprises a species selected from the group consisting of hydrogen peroxide, oxone, oxone tetrabutylammonium salt, ferric nitrate, potassium iodate, potassium permanganate, nitric acid, ammonium chlorite, ammonium chlorate, ammonium iodate, ammonium perborate, ammonium perchlorate, ammonium periodate, ammonium persulfate, sodium persulfate, potassium persulfate, tetramethylammonium chlorite, tetramethylammonium chlorate, tetramethylammonium iodate, tetramethylammonium perborate, tetramethylammonium perchlorate, tetramethylammonium periodate, tetramethylammonium persulfate, urea hydrogen peroxide, peracetic acid, and combinations thereof.
20. The method of claim 12 , further comprising rinsing the microelectronic device with deionized water following contact with the removal composition.
21. The method of claim 12 , further comprising reusing the microelectronic device, subsequent to at least partial removal of said low-k dielectric material therefrom, in another multi-layer microelectronic device manufacturing process.
22. The method of claim 12 , further comprising incorporating the microelectronic device structure into the microelectronic device.
23. The method of claim 12 , wherein the pH of a 20:1 dilution of the removal composition in water is in a range from about 2.5 to about 4.5.