Silica-based slurries containing potassium periodate (KIO4) at 0.015 M concentration, close to its solubility limit of 0.018 M, polished ruthenium at similar to 20 nm/min at an applied pressure of 2 psi. Moreover, by utilizing the increase in the solubility of KIO4 achieved by the addition of potassium hydroxide, ruthenium removal rates (RRs) were enhanced to similar to 65 nm/min at pH 9. At this pH, the toxic RuO4 does not form, making it potentially attractive for a manufacturing environment. The RRs obtained with silica abrasives are higher than those obtained with alumina abrasives at 0.015 M KIO4. A removal mechanism with KIO4 as the oxidizing agent is proposed based on the formation of several ruthenium oxides, some of which formed residues on the polishing pad below a pH of similar to 7. The removal rate selectivities of ruthenium to copper and silicon dioxide are similar to 1.3:1 and similar to 30:1, respectively. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3528942] All rights reserved.