Patent ID: 7300480

Claim:
A solution useful for removing a barrier material from a semiconductor substrate comprising by weight percent 0.01 to 25 oxidizer, 0 to 15 inhibitor for a nonferrous metal, 0 to 15 abrasive, 0 to 20 complexing agent for the nonferrous metal, 0.01 to 12 barrier removal agent selected from imine derivative compounds where the imine derivative compound is selected from formamidinesulfinic acid, 1,3-diphenyl guanidine, 1-methyl-3-nitroguanidine, guanidine hydrochloride, amino-guanidine hydrochloride, tetramethylguanidine, 2,2-azobis (dimethyl-propionamidine)di-HCl, guanidine sulfate, guanidine acetic acid, guanidine carbonate and guanidine nitrate or mixtures thereof, hydrazine derivative compounds R 3 R 4 N—NR 5 R 6 (II) where R 3 , R 4 , R 5 , and R 6 are independently —H, —OR 7 where R 7 is a hydrocarbon group, —NH 2 , a hydrocarbon group, a carbonyl group, an imido group, an azo group, a cyano group, a thio group, or a seleno group, and mixtures thereof, 0.01 to 10 organic-containing ammonium salt formed with R 1 , R 2 , R 3 and R 4 are radicals, R 1 , R 2 , R 3 and R 4 are substituted or unsubstituted aryl, alkyl, aralkyl, or alkaryl group and have a carbon chain length of 2 to 10 carbon atoms and balance water; and the solution has a pH less than 7 and a tantalum nitride to CDO selectivity of at least 2 to 1 as measured with a microporous polyurethane polishing pad with at least one pressure measured normal to a wafer of equal to or less than 13.8 kPa.