Polishing compositions for noble metals

The polishing composition of this invention is useful for chemical-mechanical polishing of substrates containing noble metals such as platinum and comprises up to about 50% by weight of a adjuvant wherein said adjuvant is selected from a group consisting of a metal-anion compound, a metal-cation compound or mixtures thereof; abrasive particles at about 0.5% to about 55% by weight of the polishing composition; and water-soluble organic additives up to about 10% by weight of the polishing composition. The abrasive particles are selected from the group consisting of alumina, ceria, silica, diamond, germania, zirconia, silicon carbide, boron nitride, boron carbide or mixtures thereof. The organic additives generally improve dispersion of the abrasive particles and also enhance metal removal rates and selectivity for metal removal by stabilizing the pH of the polishing composition and suppressing the dielectric removal rate.