Abstract: [PROBLEMS] To provide a silica sol and the method of producing the silica sol, wherein the silica sol is suitable for use as a material for, e.g., an abrasive material for electronic materials, silicon wafers or the like which are required to have a high purity, has excellent sol stability, can hence be easily made to have an increased silica concentration, and can be regulated so as to have a silica concentration equal to or higher than that of silica sols produced from water glass. [MEANS FOR SOLVING PROBLEMS] The silica sol comprises water and fine silica particles dispersed therein, and wherein the fine silica particles have a secondary-particle diameter of 10-1,000 nm, a metal impurity content of 1 ppm or lower, and a silica concentration of 10-50 wt. %. Also provided is a process for producing a stable silica sol comprising the following steps (a) and (b). (a) A first step in which a hydrolyzable silicon compound is hydrolyzed and condensation-polymerized to produce a silica sol.

Abstract: The present invention provides the colloidal silica slurry which does not have a bad influence, such as corrosion, to a silicon wafer and wiring material on a silicon wafer and inhibits growth of microbes, and whereof preserving stability is high because stability of particle diameters of a colloidal particle is superior and using for a long period continuously is possible. For providing the above, the colloidal silica slurry wherein hydrogen peroxide from 5 to 100 ppm is added.

Abstract: The present invention provides the colloidal silica slurry which does not have a bad influence, such as corrosion, to a silicon wafer and wiring material on a silicon wafer and inhibits growth of microbes, and whereof preserving stability is high because stability of particle diameters of a colloidal particle is superior and using for a long period continuously is possible. For providing the above, the colloidal silica slurry wherein hydrogen peroxide from 5 to 100 ppm is added.