MANUFACTURING METHOD OF SUBSTRATE FOR MAGNETIC RECORDING MEDIUM, AND BOTH-SURFACE POLISHER AND CARRIER FOR SUBSTRATE POLISHING USED IN THE METHOD

PROBLEM TO BE SOLVED: To reduce residual swarf after polishing by suppressing the adsorption of polishing abrasive grains to a substrate. SOLUTION: In this manufacturing method of the substrate for a magnetic recording medium, a both-surface polisher is used which polishes both surfaces of a substrate 7 by installing a carrier 6 for substrate polishing equipped with a planetary gear at its outer periphery between a sun gear 4 and an internal gear 5, and by putting the substrate 7 which is held in the substrate holding hole of the carrier 6 for substrate polishing between polishing cloths 2 which are provided on an upper surface plate 3 and a lower surface plate 4, respectively and by supplying slurry including abrasive grains and by making the carrier 6 revolve around the sun gear 4 while making the carrier 6 rotate around its own axis. The method includes a substrate polishing process which includes a slurry polishing process for polishing both the surfaces of the substrate 7 while supplying the slurry in a state that the electrical potential of the same sign as that of the zeta (ζ)-potential of the abrasive grain is impressed on the surfaces of the substrate 7 by a DC power source 15, and a washing and polishing process for washing and polishing the surfaces of the substrate 7 by supplying a washing liquid instead of the slurry in a state that the potential is impressed on each surface of the substrate 7 similarly. COPYRIGHT: (C)2006,JPO&NCIPI