Composition useful for removal of post-etch photoresist and bottom anti-reflection coatings
View Patent ↗An aqueous-based composition and process for removing hardened photoresist and/or bottom anti-reflective coating (BARC) material from a microelectronic device having same thereon. The aqueous-based composition includes at least one chaotropic solute, at least one alkaline base, and deionized water. The composition achieves high-efficiency removal of hardened photoresist and/or BARC material in the manufacture of integrated circuitry without adverse effect to metal species on the substrate, such as copper, and without damage to low-k dielectric materials employed in the microelectronic device architecture.
1. An aqueous-based removal composition for the removal of photoresist and/or bottom anti reflective coating (BARC) materials from a microelectronic device, said composition comprising at least one chaotropic solute, urea, and at least one alkaline salt in an aqueous medium, wherein the at least one chaotropic solute comprises a chaotropic species selected from the group consisting of: guanidinium salts; 2-, 3-, and 4-nitrobenzoic acid; 2-, 3-, and 4-anisic acid; 2-, 3-, and 4- fluoro-, chloro-, bromo-, and iodo-benzoic acid; 2-, 3-, and 4-methylthio -benzoic acid; 2-, 3-, and 4-methylthio-aniline; 2-, 3-, and 4-anisidine; melamine; 2,4-diamino-6-phenyl-1,3,5-triazine; 2- chloro-4,6-diamino-1,3,5-triazine; 2,4,6-trimethoxy-1,3,5-triazine; 2,4-diamino-1,3,5-triazine; 2-amino-1,3,5-triazine; 2-amino-4-ethoxy-6-(methylamino)-1,3,5-triazine; 2-methoxy-4-methyl-6-(methylamino)-1,3,5-triazine; 2-mercaptobenzimidazole; and combinations thereof, wherein the at least one alkaline salt comprises (NR 1 R 2 R 3 R 4 )OH, wherein R 1 , R 2 , R 3 and R 4 are the same as or different from one another and each is independently selected from the group consisting of hydrogen, C 1 -C 6 alkyl groups, and benzyl groups.
2. The composition of claim 1 , wherein both the at least one chaotropic solute and the at least one alkaline salt are metal-ion free.
3. The composition of claim 1 , further comprising 2-, 3-, and 4-aminobenzoic acid; 1,2,4-triazole; 2-mercaptoimidazole; and 2,4-diamino-6-methyl-1,3,5-triazine.
4. The composition of claim 1 , further comprising photoresist and/or BARC material.
5. The composition of claim 1 , further comprising co-solvent, wherein the co-solvent is selected from the group consisting of straight-chained C 1 -C 6 alcohols, branched C 1 -C 6 alcohols, diethylene glycol butyl ether, diethylene glycol methyl ether, sulfolane-w, sulfolane -A, and propylene glycol.
6. The composition of claim 1 , wherein the at least one alkaline salt comprises benzyltrimethylammonium hydroxide.
7. The composition of claim 1 , having a pH greater than about 13.
8. The composition of claim 1 , comprising:
2.9 wt. % benzyltrimethylammonium hydroxide
0.025 wt. % potassium hydroxide
22.0 wt. % sulfolane A
27.0 wt. % methyl carbitol;
17. 9 wt. % propylene glycol
1.5 wt. % urea
0.08 wt. % 2-mercaptobenzimidazole
28.595 wt. % deionized water.
9. A method of removing photoresist and/or BARC material from a substrate having said material thereon, said method comprising contacting the substrate with an aqueous-based removal composition to at least partially remove said material from the substrate, wherein the aqueous-based removal composition comprises at least one chaotropic solute, urea and at least one alkaline salt in an aqueous medium, wherein the at least one chaotropic solute comprises a chaotropic species selected from the group consisting of: guanidinium salts; 2-, 3-, and 4-nitrobenzoic acid; 2-, 3-, and 4- anisic acid; 2-, 3-, and 4-fluoro-, chloro-, bromo-, and iodo- benzoic acid; 2-, 3-, and 4-methylthio-benzoic acid; 2-, 3-, and 4-methylthio-aniline; 2-, 3-, and 4-anisidine; melamine; 2,4-diamino-6-phenyl-1,3,5-triazine; 2-chloro-4,6-diamino-1,3,5-triazine; 2,4,6-trimethoxy-1,3,5-triazine; 2,4-diamino-1,3,5-triazine; 2-amino-1,3,5-triazine; 2-amino-4-ethoxy -6-(methylamino)-1,3,5-triazine; 2-methoxy-4-methyl-6-(methylamino)-1,3,5-triazine; 2-mercaptobenzimidazole; and combinations thereof, wherein the at least one alkaline salt comprises (NR 1 R 2 R 3 R 4 )OH, wherein R 1 , R 2 , R 3 and R 4 are the same as or different from one another and each is independently selected from the group consisting of hydrogen, C 1 -C 6 alkyl groups, and benzyl groups.
10. The method of claim 9 , wherein the substrate comprises a microelectronic device structure, and wherein the material comprises a layer selected from the group consisting of: photoresist hardened by plasma etching; photoresist hardened by ion implantation; and BARC.
11. The method of claim 9 , wherein said contacting is selected from the group consisting of: time of from about 1 minute to about 60 minutes; temperature in a range of from about 40° C. to about 80° C.; and combinations thereof.
12. The method of claim 9 , wherein both the at least one chaotropic solute and the at least one alkaline salt are metal-ion free.
13. The composition of claim 1 , wherein the at least one chaotropic solute comprises 2-mercaptobenzimidazole.
14. The method of claim 9 , wherein the aqueous-based removal composition comprises:
2.9 wt. % benzyltrimethylammonium hydroxide
0.025 wt. % potassium hydroxide
22.0 wt. % sulfolane A
27.0 wt. % methyl carbitol;
17.9 wt. % propylene glycol
1.5 wt. % urea
0.08 % 2-mercaptobenzimidazole
28.595 wt. % deionized water.
15. The method of claim 9 , further comprising rinsing the substrate with deionized water following contact with the aqueous-based removal composition.
16. A method of making a microelectronic device, said method comprising removing photoresist and/or BARC layers from a microelectronic device having said material(s) thereon using the aqueous-based removal composition of claim 1 .
17. A kit comprising, in one or more containers, reagents for forming an aqueous-based removal composition, wherein said removal composition comprises at least one chaotropic solute, urea and at least one alkaline salt in an aqueous medium, wherein the at least one chaotropic solute comprises a chaotropic species selected from the group consisting of: guanidinium salts; 2-, 3-, and 4-nitrobenzoic acid; 2-, 3-, and 4- anisic acid; 2-, 3-, and 4-fluoro-, chloro-, bromo-, and iodo-benzoic acid; 2-, 3-, and 4-methylthio-benzoic acid; 2-, 3and 4-methylthio-aniline; 2-, 3-, and 4-anisidine; melamine; 2,4-diamino-6-phenyl-1,3,5-triazine; 2-chloro-4,6-diamino-1,3,5-triazine; 2,4,6-trimethoxy-1,3,5-triazine; 2,4-diamino-1,3,5-triazine; 2-amino-1,3,5-triazine; 2-amino-4-ethoxy-6-(methylamino)-1,3,5-triazine; 2-methoxy-4-methyl-6-(methylamino)-1,3,5-triazine; 2-mercaptobenzimidazole; and combinations thereof, wherein the at least one alkaline salt comprises (NR 1 R 2 R 3 R 4 )OH, wherein R 1 , R 2 , R 3 and R 4 are the same as or different from one another and each is independently selected from the group consisting of hydrogen, C 1 -C 6 alkyl groups, and benzyl groups, and wherein the kit is adapted to form an aqueous-based removal composition suitable for removing material photoresist and/or BARC material from a substrate having said material thereon.
18. The composition of claim 1 , wherein the at least one alkaline salt comprises benzyltrimethylammonium hydroxide and the at least one chaotropic solute comprises 2-mercaptobenzimidazole.