Patent ID: 7407601

Claim:
A slurry system for an improved low-K oxide/copper chemical mechanical polishing (CMP) process with low solids content to avoid copper damascene sidewall erosion and to reduce CMP impact forces comprising: an aqueous dispersion comprising particles, said particles comprising a first material having an elastomeric polymer outer surface, said first material surrounding a core comprising a second material, said second material different from said first material, said particles in said aqueous dispersion capable of exhibiting elastic behavior during the CMP process, said elastomeric polymer only on said particles in said aqueous dispersion; said aqueous dispersion having a pH of between about 7.0 and about 10.0, and, wherein said aqueous dispersion has a solids content of said particles of between about 0.5 and about 6.5 weight percent of the total weight of the aqueous dispersion.