Fujifilm Planar Solutions, LLC

Planar Solutions, LLC

Yuhu Wang

Deepak Mahulikar

Bin Hu

Liqing Wen

Saeed H Mohseni

Ken A Delbridge

Gert R M Moyaerts

Nichole R Koontz

A method for producing and using an ultrapure colloidal silica dispersion is disclosed. The ultrapure colloidal silica dispersion has less than 200 ppb of each trace metal impurity disposed therein, excluding potassium and sodium, and less than 2 ppm residual alcohol. The method comprises dissolving a fumed silica in an aqueous solvent comprising an alkali metal hydroxide to produce an alkaline silicate solution, removing the alkali metal via ion exchange to generate a silicic acid solution, adjusting temperature, concentration and pH of said silicic acid solution to values sufficient to initiate nucleation and particle growth, and cooling the silicic acid solution at a rate sufficient to produce the colloidal silica dispersion.

Ultrapure colloidal silica for use in chemical mechanical polishing applications

A method of chemical mechanical polishing a surface of a substrate including the step of: contacting the substrate and a composition including a plurality of colloidal silica particles having less than 200 ppb of each trace metal impurity, excluding potassium and sodium, have less than 2 ppm residual alcohol and wherein the cumulative concentration of the trace metal, excluding potassium and sodium, is in the range from about 0.5 to about 5 ppm; and a medium for suspending the particles; wherein the composition is an ultrapure colloidal silica dispersion; and wherein the contacting is carried out at a temperature and for a period of time sufficient to planarize the substrate.

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Santa Rosa, CA, United States of America

Yuhu Wang