Patent ID: 7968506

Claim:
A wet cleaning solvent for cleaning the trench and via openings in a dual damascene structure after the trench and via openings are dry etched, said cleaning solvent consisting essentially of: at least four of but no more than eight of the propylene glycol monomethyl ether, ethylene glycol, 1,4-butynediol, butyrolactone, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, tetrahydrothiophene-1,1-dioxide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, cyclopentanone, dimethylsulfoxide, ethylenediaminetetraacetic acid, Ethylenebis(oxyethylenenitrilo)tetraacetic acid, EGTA, trans-1,2-Diaminocyclohexane-N,N,N′,N′-tetraacetic acid hydrate, diethylenetriamine-pentaacetic acid, DTPA, 1,4,7,10-tetraazacyclododecane-tetraacetic acid, triethylenetetramine-N,N,N′,N″,N′″,N′″-hexaacetic acid, nitrilotriacetic acid, propionic acid, 1,2,3-Benzotriazole, benzene-1,2,4-tricarboxylic acid, 1,2,4-triazole, 7-methylindole-2-carboxylic acid, thioglycerol, 4-Methylmorpholine N-oxide monohydrate, isonicotinic acid N-oxide, 4-Methoxypyridine-N-oxide hydrate, 3-Hydroxypyridine-N-oxide, pyridine-N-oxide, tetramethyl ammonium hydroxide, tetraethylammonium hydroxide, tetra-n-butylammonium hydroxide, ammonium fluoride, tetrabutylammonium fluoride, and 1,3-dimethyl-2-imidazolidinone, wherein the wet cleaning solvent comprises less than 500 ppb of each of the following trace elements: Al, Ca, Cr, Cu, Fe, Pb, Li, Mg, Mn, Ni, K, and Na.