MODIFIED COLLOIDAL SILICA AND METHOD FOR PRODUCING THE SAME, AND POLISHING AGENT USING THE SAME

• US 20190309191A1
• Filed: 06/21/2019
• Published: 10/10/2019
• Est. Priority Date: 01/19/2015
• Status: Abandoned Application

• Current Assignee: Fujimi Incorporated
• Original Assignee: Fujimi Incorporated
• Inventors: ASHITAKA, Keiji, TSUBOTA, Shogo
• Application Number:
  US16/449,011
• Publication Number:
  US 20190309191A1
• Time in Patent Office: Days
• CPC Class Codes: B24B 37/00 Lapping machines or devices; Accessories B24B3/00 takes precedence
• CPC Class Codes: B24B 37/044 characterised by the composition of the lapping agent
• CPC Class Codes: C01B 33/146 After-treatment of sols preparation of hydrosols or aqueous dispersions from hydroorganosols, organosols or dispersions in an organic medium C01B33/141; preparation of hydroorganosols, organosols or dispersions in an organic medium from hydrosols or aqueous dispersions C01B33/145
• CPC Class Codes: C01B 33/148 Concentration; Drying; Dehydration; Stabilisation; Purification C01B33/1465 takes precedence
• CPC Class Codes: C01B 33/149 Coating
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2004/51 Particles with a specific particle size distribution
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C07F 7/025 without C-silicon linkages
• CPC Class Codes: C09G 1/02 containing abrasives or grinding agents abrasives as such C09K3/14; polishing of semi-conductors H01L
• CPC Class Codes: C09K 3/14 Anti-slip materials; Abrasives products specifically intended for the fabrication of abrasive tools, blocks or papers, or for operations of the kind of sand-blasting and barrelling B24B31/14, B24C1/00; polishing compositions containing abrasive or grinding agents C09G1/02; polishing of semi-conductors H01L; friction compositions for brakes or clutches F16D69/02
• CPC Class Codes: C09K 3/1436 Composite particles, e.g. coated particles
• CPC Class Codes: H01L 21/304 Mechanical treatment, e.g. grinding, polishing, cutting H01L21/30625 takes precedence
• CPC Class Codes: H01L 21/31053 involving a dielectric removal step
• CPC Class Codes: H01L 21/76819 Smoothing of the dielectric planarisation of insulating materials per se H01L21/31051

Abstract

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.

Claims

1-15. -15. (canceled)

16. A polishing agent, comprising:

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.

17. A polishing agent, comprising the modified colloidal silica set forth in claim 16, wherein the modified colloidal silica is anionically modified.

18. A polishing agent, comprising the modified colloidal silica set forth in claim 17, wherein the modified colloidal silica is modified with a sulfonic acid group.

19. A polishing agent, comprising:

modified colloidal silica being anionically modified, wherein when a SiN wafer is subjected to an immersion treatment under a pH 2 condition and then washed with pure water, the number of particles having a particle size of less than 40% of a volume average particle size adhering to a surface of the SiN wafer is 50% or less relative to the number of particles having a particle size of 40% or more of a volume average particle size adhering similarly.

21. A polishing agent, comprising the modified colloidal silica set forth in claim 19, wherein the total content of metal impurities is 1 ppm by mass or less.

20. A polishing agent, comprising:

modified colloidal silica being cationically modified, wherein when an aluminosilicate glass wafer is subjected to an immersion treatment under a pH 4 condition and then washed with pure water, the number of particles having a particle size of less than 40% of a volume average particle size adhering to a surface of the aluminosilicate glass wafer is 50% or less relative to the number of particles having a particle size of 40% or more of a volume average particle size adhering similarly.