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 cleaning formulation comprising (i) a fluoride source, (ii) at least one organic amine, (iii) a nitrogen-containing carboxylic acid or an imine, (iv) water, and optionally at least one metal chelating agent, wherein the nitrogen-containing carboxylic acid or imine is 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 cleaning formulation of claim 1 , wherein the wafer cleaning composition has a pH greater than 7.
3. The cleaning formulation 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 cleaning formulation of claim 1 , wherein the fluoride source comprises a fluoride species selected from the group consisting of:
any combination of ammonia gas or ammonium hydroxide and hydrogen fluoride gas or hydrofluoric acid,
ammonium bifluoride,
ammonium fluoride,
triethanolammonium fluoride (TEAF),
diglycolammonium fluoride (DGAF),
tetramethylammonium fluoride (TMAF),
methyldiethanolammonium fluoride (MDEAF), and
triethylamine tris(hydrogen fluoride) (TREAT-HF).
5. The cleaning formulation of claim 1 , wherein the amount of fluoride source is 1-35% weight percent, based on the total weight of the composition.
6. The cleaning formulation 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-aminoethoxyl)ethanol.
7. The cleaning formulation of claim 1 , wherein the amount of organic amine(s) is 20-60% weight percent, based on the total weight of the composition.
8. The cleaning formulation of claim 1 , wherein the amount of water is 20-50% weight percent, based on the total weight of the composition.
9. The cleaning formulation 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.
10. The cleaning formulation of claim 1 , wherein the amount of at least one metal chelating agent is 0-21% weight percent, based on the total weight of the composition.
11. The cleaning formulation of claim 1 , 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.
12. The cleaning formulation of claim 11 , 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.
13. The cleaning formulation of claim 1 , wherein the nitrogen-containing carboxylic or imine comprises iminodiacetic acid.