| 摘要 |
PROBLEM TO BE SOLVED: To provide a new colloidal silica which is produced easier at a lower cost, contaminated less with metal impurities than the conventional ones, and used for polishing electronic materials such as silicon wafers, compound semiconductor wafers, semiconductor device wafers, magnetic disc substrates and crystal substrates. SOLUTION: The colloidal silica includes core-shell type silica particles composed of silica particles of a colloidal silica obtained from a water-solution of an alkali silicate as the core and a 1-10 nm thick shell composed of a silica which is obtained by hydrolyzing tetraalkoxysilane with an alkali catalyst and covers the surface of the core. COPYRIGHT: (C)2011,JPO&INPIT |
