LUDOX^® Colloidal Silica for Wafer Polishing

Slurry formulations containing colloidal silica are effective polishing agents for silicon semiconductor wafers due to high degree of alkalinity and silica surface area.

It is generally believed that the polishing action of aqueous colloidal silica on silicon wafers is a combination of

• Chemical etching, and
• Mechanical abrasion

The silicon surface is oxidized, either by oxygen or by an added oxidant in the presence of the alkali in the LUDOX^® colloidal silica; the rate of reaction increases in conjunction with the pH of the polishing solution.

The silicate formed by this oxidation process is rapidly and completely removed by adsorption on or reaction with the surface of the colloidal silica particles.