Polmer-coated particles for chemical mechanical polishing

A polishing composition suitable for chemical mechanical polishing magnetic, optical, semiconductor or silicon substrates comprising:

• abrasive particles in a liquid media, the abrasive particles having a particle core, the particle core having a hardness;
• a polymeric shell physisorbed to and encapsulating the particle core, the polymeric shell having a solid crosslinked polymeric structure that encapsulates the particle core, a hardness lower than the hardness of the particle core and a thickness of 0.5 to 20 nanometers;
• and wherein the abrasive particles have an average particle size of less than or equal to about 2 micrometers dispersed in the liquid media and the abrasive particles have hybrid polishing properties of the polymeric shell and particle core the hybrid polishing properties being different in comparison to polishing properties of the particle core and different in comparison to polishing properties of particles of the polymeric shell.