Chemical mechanical polishing composition containing composite silica particles, method of making the silica composite particles and method of polishing a substrate

A method for chemical mechanical polishing of a substrate, comprising:

• providing a substrate, wherein the substrate comprises dielectric materials of silicon oxide, silicon nitride and polysilicon;
• providing an acid chemical mechanical polishing composition according to claim 1 comprising:
• water;
• colloidal silica abrasive particles comprising a silica core comprising a nitrogen species, a cerium compound comprising cerium oxide, cerium hydroxide, or mixtures thereof
• coating the silica core, and a positive zeta potential;
• an oxidizing agent;
• optionally a pH adjusting agent;
• optionally a biocide;
• optionally a surfactant;
• and
• a pH less than 7;
• providing a chemical mechanical polishing pad with a polishing surface;
• creating dynamic contact at an interface between the polishing surface of the acid chemical mechanical polishing pad and the substrate with a down force of 0.69 to 34.5 kPa;
• and
• dispensing the acid chemical mechanical polishing composition onto the chemical mechanical polishing pad at or near the interface between the chemical mechanical polishing pad and the substrate;
• wherein the substrate is polished;
• and, wherein the silicon dioxide is removed from the substrate at enhanced removal rates over silicon nitride and polysilicon.