PREPARATION METHOD OF SLURRY FOR POLISHING DIELECTRIC LAYER OF WAFER

摘要

PURPOSE: A preparation method of slurry is disclosed having an excellent polishing rate and a micro-scratch property in polishing a dielectric layer of a wafer. CONSTITUTION: A slurry is prepared from dispersing an ammonium salt in a silica polishingparticle. The silica is a fumed silica obtained by high-temperature oxidation method and has a mean particle size of 5 to 80 nanometer. The ammonium salt is used for controlling the particle size and includes alkyl trimethyl ammonium chloride or alkyl trimethyl ammonium bromide, where the alkyl group has a carbon number of C1 to C30. The addition amount of the ammonium salt is from 0.001 to 0.5 percent by weight relative to that of the silica.