Patent ID: 8167685

Claim:
A method of manufacturing a perpendicular magnetic recording medium comprising, in succession: a preliminary polishing process to smooth an underlayer made of Ni—P alloy on a substrate, a 2-step texturing process: a first texturing process using a nonwoven fabric tape and a slurry of polycrystalline diamond slurry and surfactant to form a plurality of grooves on an underlayer made of a Ni—P alloy that is on a substrate using a first polishing tape made of nonwoven fabric while supplying a first slurry that contains a surfactant and a first abrasive material; and a second texture polishing in which a surface of the underlayer processed by the texturing process is polished to have a surface roughness comprising texture traces that promote magnetization alignment in a vertical direction, using a second polishing tape made of a porous material while supplying a second slurry containing an acid citric, malic, maleic, phosphoric, succinic, or formic acid or a mixture thereof and colloidal silica a second abrasive material having a grain diameter smaller than a mean diameter of perforations of the second polishing tape wherein the second abrasive material is colloidal silica; and a sputtering process to deposit first a non-magnetic layer and then a magnetic layer on the textured surface.