Patent ID: 7253111

Claim:
A polishing solution useful for preferentially removing barrier materials in the presence of nonferrous interconnect metals with limited erosion of dielectrics comprising: 0 to 20 weight percent oxidizer, at least 0.001 weight percent inhibitor for reducing removal rate of the nonferrous interconnect metals, 10 ppb to 4 weight percent complexing agent, 1 to 4 weight percent organic-containing ammonium salt formed with wherein R 1 , R 2 , R 3 and R 4 are organic radicals and R 1 has a cardon chain length of 2 to 5 carbon atoms, 0.1 to 50 weight percent colloidal silica abrasive and balance water; and the solution having a pH of less than 7; and the polishing solution being useful for removing a barrier layer with limited erosion of a dielectric material.