Chemical Mechanical Polishing (CMP) Composition for Shallow Trench Isolation (STI) Applications and Methods of Making Thereof

A method of reducing trace metal contaminants, smaller and bigger sized cerium oxide particles in a cerium oxide slurry, the method comprising at least one of the following steps (I) to (V):

• (I) (a) adding an ion exchange resin to the cerium oxide slurry;
• and (b) removing the ion exchange resin through filtration to obtain treated cerium oxide slurry;
• wherein the ion exchange resin is a cationic ion exchange resin or an anionic ion exchange resin;
• (II) running deionized water through the cerium oxide slurry using at least one ultra filtration membrane to obtain a treated cerium oxide slurry as retentate;
• (III) (a) centrifuging the cerium oxide slurry;
• (b) collecting cerium oxide particles from the precipitate of centrifugation;
• and (c) mixing deionized water with the collected cerium oxide particles to form a treated cerium oxide slurry;
• (IV) (a) adding a chemical additive to the cerium oxide slurry to form a mixture, wherein the chemical additive reacts with trace metal ions in the trace metal contaminants to form water soluble chemical additive-metal ion complexes;
• (b) centrifuging the mixture;
• (c) collecting cerium oxide particles from the precipitate of the centrifugation;
• and (d) mixing deionized water with the collected cerium oxide particles to obtain a treated cerium oxide slurry.