Abstract: A system for removing particles or deposits from a surface having particles or deposits thereon, the system comprising at least one vessel, at least one enclosure containing a surface having particles or deposits thereon, one or more pumps, and one or more valves; the at least one vessel suitable for holding a chemical composition; wherein the at least one vessel is in fluid communication with the at least one enclosure, and the at least one enclosure is in fluid communication with the at least one vessel, to form at least a primary chemical composition circulation loop.

Abstract: An ultrapure colloidal silica dispersion comprising colloidal silica particles having a mean or aggregate particle size from about 10 to about 200 nm, wherein the colloidal silica dispersion has less than 200 ppb of each trace metal impurity disposed therein, excluding potassium and sodium, and have less than 2 ppm residual alcohol.

Abstract: 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.

Abstract: A composition for chemical mechanical polishing a surface of a substrate having a plurality of ultra high purity sol gel processed colloidal silica particles for chemical mechanical polishing having alkali metals Li, Na, K, Rb, Cs, Fr and a combination thereof, at a total alkali concentration of about 300 ppb or less, with the proviso that the concentration of Na, if present, is less than 200 ppb; and a medium for suspending the particles is provided. Also, provided are methods of chemical mechanical polishing which included a step of contacting a substrate and a composition according to the present invention. The contacting is carried out at a temperature and for a period of time sufficient to planarize the substrate.