Aqueous cleaning composition containing copper-specific corrosion inhibitor for cleaning inorganic residues on semiconductor substrate
View Patent ↗A semiconductor wafer cleaning formulation, including 1-35% wt. fluoride source, 20-60% wt. organic amine(s), 0.1-40% wt. nitrogenous component, e.g., a nitrogen-containing carboxylic acid or an imine, 20-50% wt. water, and 0-21% wt. metal chelating agent(s). The formulations are useful to remove residue from wafers following a resist plasma ashing step, such as inorganic residue from semiconductor wafers containing delicate copper interconnecting structures.
1. A method of making an integrated circuit containing a copper containing substrate, comprising contacting said substrate with a wafer cleaning formulation, wherein said wafer cleaning formulation comprises at least one amine and a nitrogen-containing carboxylic acid or an imine selected from the group consisting of:
iminodiacetic acid (IDA),
glycine,
1,1,3,3-tetramethylguanidine (TMG),
CH 3 C(═NCH 2 CH 2 OH)CH 2 C(O)N(CH 3 ) 2 ,
CH 3 C(═NCH 2 CH 2 OCH 2 CH 2 OH)CH 2 C(O)N(CH 3 ) 2 ,
CH 3 C(═NH)CH 2 C(O)CH 3 ,
(CH 3 CH 2 ) 2 NC(═NH)N(CH 3 CH 2 ) 2 ,
HOOCCH 2 N(CH 3 ) 2 , and
HOOCCH 2 N(CH 3 )CH 2 COOH.
2. The method of claim 1 , wherein the wafer cleaning composition has a pH greater than 7.
3. The method of claim 1 , wherein the amount of nitrogen-containing carboxylic acid or imine is 0.1-40 weight percent, based on the total weight of the composition.
4. The method of claim 1 , wherein the wafer cleaning composition further comprises a fluoride source.
5. The method of claim 4 , wherein the fluoride source comprises a fluoride species selected from the group consisting of:
ammonium bifluoride,
ammonium fluoride,
triethanolammonium fluoride (TEAF),
diglycolammonium fluoride (DGAF),
tetramethylammonium fluoride (TMAF),
methyldiethanolammonium fluoride (MDEAF), and
triethylamine tris(hydrogen fluoride) (TREAT-HF).
6. The method of claim 4 , wherein the amount of fluoride source is 1-35% weight percent, based on the total weight of the composition.
7. The method of claim 1 , wherein the organic amine(s) comprise an amine(s) selected from the group consisting of:
diglycolamine (DGA),
methyldiethanolamine (MDEA),
pentamethyldiethylenetriamine (PMDETA),
triethanolamine (TEA),
triethylenediamine (TEDA),
hexamethylenetetramine,
3,3-iminobis(N,N-dimethylpropylamine),
monoethanolamine,
2-(methylamino)ethanol,
4-(2-hydroxyethyl)morpholine,
4-(3-aminopropyl)morpholine, and
N,N-dimethyl-2-(2-aminoethoxy)ethanol.
8. The method of claim 1 , wherein the amount of organic amine(s) is 20-60% weight percent, based on the total weight of the composition.
9. The method of claim 1 , wherein the wafer cleaning formulation further comprises water.
10. The method of claim 9 , wherein the amount of water is 20-50% weight percent, based on the total weight of the composition.
11. The method of claim 1 , wherein the wafer cleaning formulation further comprises at least one metal chelating agent selected from the group consisting of:
acetoacetamide,
ammonium carbamate,
ammonium pyrrolidinedithiocarbamate (APDC),
dimethyl malonate,
methyl acetoacetate,
N-methyl acetoacetamide,
2,4-pentanedione,
1,1,1,5,5,5-hexafluoro-2,4-pentanedione H(hfac),
2,2,6,6-tetrammethyl-3,5-heptanedione H(thd),
tetramethylammonium thiobenzoate,
tetramethylammonium trifluoroacetate,
tetramethylthiuram disulfide (TMTDS),
trifluoracetic acid,
lactic acid,
ammonium lactate,
malonic acid,
formic acid,
acetic acid,
propionic acid,
gamma-butyrolactone,
iminodiacetic acid,
methyldiethanolammonium trifluoroacetate, and
trifluoroacetic acid.
12. The method of claim 11 , wherein the amount of at least one metal chelating agent is 0-21% weight percent, based on the total weight of the composition.
13. The method of claim 4 , wherein said fluoride source comprises a compound having the general formula R 1 R 2 R 3 R 4 NF in which each of the R groups is independently selected from hydrogen atoms, C 1 -C 8 alkyl, aryl and alkenyl groups, and wherein said formulation includes a metal chelating agent of the formula:
X—CHR—Y
in which R is either hydrogen, C 1 -C 8 alkyl, aryl or alkenyl group and X and Y are functional groups containing multiply bonded moieties having electron-withdrawing properties.
14. The method of claim 13 , wherein each of X and Y is independently selected from CONH 2 , CONHR′, CN, NO 2 , SOR′, and SO 2 Z in which R′ is C 1 -C 8 alkyl and Z is hydrogen, halo, or C 1 -C 8 alkyl.
15. The method of claim 4 , wherein said fluoride source comprises a compound having the formula R 1 R 2 R 3 R 4 NF in which each of the R groups is hydrogen, C 1 -C 8 alkyl, aryl or alkenyl groups, and wherein said formulation includes a metal chelating agent of the formula, R 1 R 2 R 3 R 4 N +− O 2 CCF 3 in which each of the R groups is independently hydrogen, C 1 -C 8 alkyl, aryl or alkenyl groups.
16. The method of claim 1 , wherein the substrate comprises copper.
17. The method of claim 1 , further comprising a fluoride source, water, and optionally metal chelating agent(s).
18. The method of claim 17 , comprising triethanolamine, triethanolammonium fluoride, pentamethyldiethylenetriamine, iminodiacetic acid, ammonium bifluoride and water.
19. The method of claim 1 , wherein the substrate contacted with the wafer cleaning formulation comprises slurry particles remaining after chemical mechanical polishing.