Polishing composition

Abstract

The present invention relates to a polishing composition containing an aqueous medium and silica particles, wherein the silica particles in the polishing composition has a zeta potential of from −15 to 40 mV; a method for manufacturing a substrate including the step of polishing a substrate to be polished with a polishing composition containing an aqueous medium and silica particles, wherein the silica particles in the polishing composition has a zeta potential of from −15 to 40 mV; and a method for reducing scratches on a substrate to be polished with a polishing composition containing an aqueous medium and silica particles, including the step of adjusting a zeta potential of silica particles in the polishing composition to −15 to 40 mV. The polishing composition can be favorably used in polishing the substrate for precision parts, including substrates for magnetic recording media such as magnetic discs, optical discs and opto-magnetic discs; photomask substrates; optical lenses; optical mirrors; optical prisms; semiconductor substrates; and the like.

1 . A method for reducing scratches on a substrate to be polished with a polishing composition comprising an aqueous medium and silica particles, comprising the step of adjusting a zeta potential of silica particles in the polishing composition to −15 to 40 mV.  
   
   
       2 . The method according to  claim 1 , wherein the silica particles have an average primary particle size of 1 nm or more and less than 40 nm.  
   
   
       3 . The method according to  claim 1 , wherein the substrate to be polished is a memory hard disk substrate.  
   
   
       4 . The method according to  claim 1 , further comprising the step of pressing a polishing pad against the substrate to be polished while feeding the polishing composition at a rate of from 0.01 to 3 mL/minute per 1 cm 2  of the substrate to be polished.