Patent ID: 7056192

Claim:
A slurry for performing chemical mechanical polishing (CMP) of oxides on a substrate, comprising: ceria particles having a first concentration; and silica particles having a second concentration, wherein the concentration of ceria in the slurry is approximately 1.0–5.0 wt %; the concentration of silica in the slurry is approximately 0.1–5.0 wt %; wherein a ratio of ceria concentration to silica concentration (ceria:silica) is from approximately 10:1 to nearly 1:1 by weight; the ceria particles have a particle size of 150–250 nm; and the silica particles have a particle size greater than 100 nm; wherein the silica particles comprise fumed silica; and wherein the slurry has a pH in the range of from 7–12.