Abstract: A chemical mechanical polishing slurry containing multiple oxidizers and nano abrasive particles (including engineered nano diamond particles) suitable for polishing multilayer substrate with tungsten and Ti/TiN barrier layers. The slurry contains no metallic catalyst and has low total abrasive particle content. The absence of metal ions can be advantageous for certain applications as certain metal ions may present contamination issues. A low total abrasive content may also lower the total defect counts, reduce the slurry waste treatment burden, and simplify the post CMP clean process.