Patent ID: 7828628
Filing Date: 2010-11-09
Classification: B24B,C09G,C09K,H01L

Abstract:
1. A method of polishing a hard crystal substrate, said method comprising: a rough polishing process of polishing a surface of said substrate such that said surface comes to have an average surface roughness of 0.5 nm or more and 1 nm or less; and a finishing process, carried out after said rough polishing process, of polishing said surface such that the average surface roughness of said surface becomes 0.2 nm or less; wherein said finishing process comprises the steps of: rotating a lapping plate; supplying polishing oil slurry to a surface of said lapping plate; pressing the surface of said hard crystal substrate onto the surface of said lapping plate and rotating said hard crystal substrate; wherein said polishing oil slurry comprises abrading particles and an oil dispersant that disperses said abrading particles; wherein said abrading particles include artificial diamond clusters that comprise approximately spherical agglomerate particles, said agglomerate particles having average particle size D50 of 20 nm or more and 50 nm or less and comprising primary particles diameters of 2 nm or more and 10 nm or less.