A method for producing a silica composite particle including a silica particle and at least one compound in which an aluminum atom bonds to an organic group through oxygen. The method includes: (i) providing a silica particle dispersion liquid having a silica particle content of about 20 mass % or more; (ii) mixing and reacting a compound represented by formula (S1) and the silica particle dispersion liquid to obtain a slurry; (iii) providing the at least one compound; and (iv) then mixing and reacting the slurry with the at least one compound to form the silica composite particle.

A method for producing a silica composite particle including a silica particle and at least one compound in which an aluminum atom bonds to an organic group through oxygen. The method includes: (i) providing a silica particle dispersion liquid having a silica particle content of about 20 mass % or more; (ii) mixing and reacting a compound represented by formula (S1) and the silica particle dispersion liquid to obtain a slurry; (iii) providing the at least one compound; and (iv) then mixing and reacting the slurry with the at least one compound to form the silica composite particle.

To provide modified colloidal silica capable of improving the stability of the polishing speed with time when used as abrasive grains in a polishing composition for polishing a polishing object that contains a material to which charged modified colloidal silica easily adheres, such as a SiN wafer, and to provide a method for producing the modified colloidal silica. Modified colloidal silica, being obtained by modifying raw colloidal silica, wherein the raw colloidal silica has a number distribution ratio of 10% or less of microparticles having a particle size of 40% or less relative to a volume average particle size based on Heywood diameter (equivalent circle diameter) as determined by image analysis using a scanning electron microscope.

To provide modified colloidal silica capable of improving the stability of the polishing speed with time when used as abrasive grains in a polishing composition for polishing a polishing object that contains a material to which charged modified colloidal silica easily adheres, such as a SiN wafer, and to provide a method for producing the modified colloidal silica. Modified colloidal silica, being obtained by modifying raw colloidal silica, wherein the raw colloidal silica has a number distribution ratio of 10% or less of microparticles having a particle size of 40% or less relative to a volume average particle size based on Heywood diameter (equivalent circle diameter) as determined by image analysis using a scanning electron microscope.

Modified silanized colloidal silica particles are reaction products of silanized colloidal silica particles having epoxy moieties with nitrogen of amines to form stable and tunable modified silanized colloidal silica particles. The modified silanized colloidal silica particles can be used as an abrasive in chemical mechanical polishing of various substrates.

Modified silanized colloidal silica particles are reaction products of silanized colloidal silica particles having epoxy moieties with nitrogen of amines to form stable and tunable modified silanized colloidal silica particles. The modified silanized colloidal silica particles can be used as an abrasive in chemical mechanical polishing of various substrates.

Silica particles include a nitrogen-containing compound. When the volumes of pores having a diameter of 1 nm or more and 50 nm or less, the volumes being determined from a pore size distribution curve of the silica particles before and after the silica particles are baked at 350° C., the pore size distribution curve being obtained by nitrogen gas adsorption, are defined as A and B, respectively, B/A is 1.2 or more and 5 or less and B is 0.2 cm.sup.3/g or more and 3 cm.sup.3/g or less.

Silica particles include a nitrogen-containing compound. When the volumes of pores having a diameter of 1 nm or more and 50 nm or less, the volumes being determined from a pore size distribution curve of the silica particles before and after the silica particles are baked at 350° C., the pore size distribution curve being obtained by nitrogen gas adsorption, are defined as A and B, respectively, B/A is 1.2 or more and 5 or less and B is 0.2 cm.sup.3/g or more and 3 cm.sup.3/g or less.

To provide modified colloidal silica capable of improving the stability of the polishing speed with time when used as abrasive grains in a polishing composition for polishing a polishing object that contains a material to which charged modified colloidal silica easily adheres, such as a SiN wafer, and to provide a method for producing the modified colloidal silica.

Modified colloidal silica, being obtained by modifying raw colloidal silica, wherein

the raw colloidal silica has a number distribution ratio of 10% or less of microparticles having a particle size of 40% or less relative to a volume average particle size based on Heywood diameter (equivalent circle diameter) as determined by image analysis using a scanning electron microscope.

To provide modified colloidal silica capable of improving the stability of the polishing speed with time when used as abrasive grains in a polishing composition for polishing a polishing object that contains a material to which charged modified colloidal silica easily adheres, such as a SiN wafer, and to provide a method for producing the modified colloidal silica.

Modified colloidal silica, being obtained by modifying raw colloidal silica, wherein

the raw colloidal silica has a number distribution ratio of 10% or less of microparticles having a particle size of 40% or less relative to a volume average particle size based on Heywood diameter (equivalent circle diameter) as determined by image analysis using a scanning electron microscope.