2results about How to "Improve the selection ratio" patented technology

Provided is a ceria particle for chemical mechanical polishing, and a slurry composition for chemical mechanical polishing containing the same. The surface of the ceria particle contains Ce 3+ and Ce 4+ When the ceria particle of the embodiment of the present application is used, by increasing the proportion of Ce 3+ on the surface of ceria, a high oxide film removal rate and an oxide film polishing selectivity ratio can be exhibited in a low content range, despite a small particle size.

This invention provides a cerium oxide-based polishing slurry for STI structures. The slurry comprises, by total mass, 0.05 wt%–5 wt% nano-cerium dioxide abrasive, 0.02 wt%–0.2 wt% hydroquinone, 0.05 wt%–0.25 wt% pyridinecarboxylic acid, 0.01 wt%–0.5 wt% D-sorbitol, and 0.001 wt%–0.01 wt% 1,2-benzisothiazolin-3-one, with a pH of 3–5. The cerium oxide-based polishing slurry provided by this invention, by adding a reducing agent to gently fine-tune the CeO2 surface activity to increase the Ce3+ content, promotes the removal rate of TEOS. Through the synergistic effect of other inhibitors and passivators, a high TEOS:Si3N4 selectivity ratio is obtained. Inhibiting the removal rate of Si3N4 indirectly avoids excessive grinding of oxides in the trenches, resulting in better wafer surface planarization efficiency.