| abstract |
The polishing solution is useful for preferentially removing barrier materials in the presence of nonferrous interconnect metals with limited erosion of dielectrics. The polishing solution comprises 0 to 20 weight percent oxidizer, inhibitor for reducing removal rate of the nonferrous interconnect metals, ammonium salt, 0.1 to 50 weight percent silica containing 0.001 to 1 ppm sodium and 0.001 to 1 ppm potassium, and balance water; and the solution having a pH of less than 3 with an inorganic acid used as a titrant. |