A composition for chemical-mechanical planarization comprises periodic
acid and an abrasive present in a combined amount sufficient to planarize
a substrate surface having a feature thereon comprising a noble metal,
noble metal alloy, noble metal oxide, or any combination thereof. In one
embodiment, the periodic acid is present in an amount in a range of from
about 0.05 to about 0.3 moles/kilogram, and the abrasive is present in an
amount in a range of from about 0.2 to about 6 weight percent. In another
embodiment, the composition further comprises a pH-adjusting agent
present in an amount sufficient to cause the pH of the composition to be
in a range of from about pH 5 to about pH 10, or of from about pH 1 to
about pH 4. A method for planarizing a substrate surface having a feature
thereon comprising at least one noble metal, noble metal alloy, or noble
metal oxide, or a combination thereof, comprises providing a composition
or slurry comprising periodic acid and an abrasive in a combined amount
sufficient to planarize the substrate surface, and polishing the surface
with the slurry. A substrate produced by such a method is also provided.