Microelectronic cleaning compositions containing ammonia-free fluoride salts for selective photoresist stripping and plasma ash residue cleaning
View Patent ↗Ammonia-free, HF-free cleaning compositions for cleaning photoresist and plasma ash residues from microelectronic substrates, and particularly to such cleaning compositions useful with and having improved compatibility with microelectronic substrates characterized by sensitive porous and low-κ to high-κ dielectrics and copper metallization. The cleaning composition contain one or more non-ammonium producing, non-HF producing fluoride salt (non ammonium, quaternary ammonium fluoride salt) in a suitable solvent matrix.
1. A cleaning composition capable of cleaning photoresist or plasma etch or ash residue from a microelectronic substrate having copper metallization and at least one of a porous dielectric, a low-κ or high-κ dielectric, said cleaning composition consisting of:
from about 0.05 to 20% by weight of one or more tetraalkylammonium fluoride salts of the formula
(R) 4 N + F −
wherein each R is independently a substituted or unsubstituted alkyl group;
from about 5 to about 99.95% by weight of at least one polar, water miscible, copper/low-κ compatible organic solvent or both water and said at least one polar, water miscible, copper/low-κ compatible organic solvent, wherein said at least one organic solvent is selected from the group consisting of dimethyl sulfoxide, sulfolane, dimethyl piperidone, 1-(2-hydroxyethyl)-2-pyrrolidinone, 1-methyl-2-pyrrolidinone, dimethylacetamide, acetonitrile and isobutylnitrile;
from about 5 to about 80% by weight of a metal corrosion inhibiting solvent selected from the group consisting of ethylene glycol, diethylene glycol, glycerol, diethylene glycol dimethyl ether, triethanolamine, N,N-dimethylethanolamine, 1-(2-hydroxyethyl)-2-pyrrolidinone, 4-(2-hydroxyethyl)morpholine, 2-(methylamino)ethanol, 2-amino-2-methyl-1-propanol, 1-amino-2-propanol, 2-(2-aminoethoxy)-ethanol, N-(2-hydroxyethyl)acetamide, N-(2-hydroxyethyl) succinimide and 3-(diethylamino)-1,2-propanediol;
from about 0 to 40% by weight of an other metal corrosion inhibitor compound selected from the group consisting of benzotriazole and aryl compounds containing 2 or more OH or OR groups where R is selected from the group consisting of alkyl or aryl groups;
from about 0 to 5% by weight of a surfactant;
from about 0 to 10% by weight of a metal ion free silicate compound; and
from about 0 to 5% by weight of a metal chelating agent selected from the group consisting of the organic acids (ethylenedinitrilo)tetraacetic acid (EDTA), butylenediaminetetraacetic acid, (1,2-cyclohexylenedinitrilo)tetraacetic acid (CyDTA), diethylenetriaminepentaacetic acid (DETPA), ethylenediaminetetrapropionic acid, (hydroxyethyl)ethylenediaminetriacetic acid (HEDTA), N,N,N′,N′-ethylenediaminetetra(methylenephosphonic) acid (EDTMP), triethylenetetraminehexaacetic acid (TTHA), 1,3-diamino-2-hydroxypropane-N,N,N′,N′-tetraacetic acid (DHPTA), methyliminodiacetic acid, propylenediaminetetraacetic acid, nitrolotriacetic acid (NTA), citric acid, tartaric acid, gluconic acid, saccharic acid, glyceric acid, oxalic acid, phthalic acid, maleic acid, mandelic acid, malonic acid, lactic acid, salicylic acid, catechol, gallic acid, propyl gallate, pyrogallol, 8-hydroxyquinoline, and cysteine, and their isomers and salts.
2. A composition according to claim 1 wherein R of the tetraalkylammonium fluoride is an alkyl group containing 1 to 22 carbon atoms.
3. A composition according to claim 2 wherein R of the tetraalkylammonium fluoride is an alkyl group of from 1 to 6 carbon atoms.
4. A composition according to claim 1 wherein the tetraalkylammonium fluoride is a tetramethylammonium fluoride.
5. A composition according to claim 1 wherein the solvent comprises water and said at least one polar, water miscible, copper/low-κ compatible organic solvent selected from the group consisting of 1-(2-hydroxyethyl)-2-pyrrolidinone dimethyl sulfoxide, sulfolane, and dimethyl piperidone.
6. A composition according to claim 1 wherein the cleaning composition consists of tetramethylammonium fluoride, dimethyl sulfoxide, 1-(2-hydroxyethyl)-2-pyrrolidinone, water, triethanolamine and benzotriazole.