Patent ID: 7201784

Claim:
A slurry for polishing copper comprising: an ester carboxylate based surfactant that includes a hydrophobic tail and a hydrophilic bead that has a negative charge, wherein the ester carboxylate based surfactant is selected from the group consisting of ammonium laureth-7-tartrate, potassium laureth-7-tartrate, ammonium laureth-7-citrate, and potassium laureth-7-citrate; and, an abrasive comprising negatively charged silica particles, wherein the ester carboxylate based surfactant is combined with the abrasive comprising negatively charged silica particles so that the hydrophilic head is not attracted to the negatively charged silica particles thus minimizing agglomeration of the silica and prevents bent line defects in a substrate comprising copper and a low k dielectric material when polished with the ester carboxylate based surfactant and the abrasive comprising silica.