Patent ID: 9142238
Filing Date: 2015-09-22
Classification: G11B

Abstract:
1. A method of manufacturing a vertical magnetic recording disk comprising at least a magnetic recording layer on a substrate and used for vertical magnetic recording at a density greater than 100 Gb/in 2 , said method comprising: providing the substrate; and forming, on the substrate, the magnetic recording layer, said forming step further comprising (a) forming a ferromagnetic layer having a granular structure and (b) forming an exchange energy control layer on the ferromagnetic layer, wherein at least the exchange energy control layer is formed through sputtering in an atmosphere of a rare gas having a greater mass than an argon gas, said sputtering being conducted at a gas pressure in a range of 1-10 m Torr and producing said energy control layer having a thickness of 2-5 nm, wherein the exchange energy control layer is a laminated layer consisting of a plurality of first layers consisting of Co or a Co-alloy and a plurality of second layers consisting of palladium (Pd) with said rare gas embedded therein, whereby the surface roughness of the disk having an exchange energy control layer that is formed through sputtering in an atmosphere of a rare gas having a greater mass than an argon gas, as determined by Ra and Rmax as measured by AFM, is less than that where an exchange energy control layer is formed through sputtering in an atmosphere of argon, whereby the coercive force (Hc) of the resulting structure is equal to or greater than 4300 Oe, wherein the magnetization reversal nucleation field (Hn) of the disk is −1300 Oe or smaller, wherein the ferromagnetic layer has a crystal grain containing cobalt (Co) as a main constituent and a grain boundary portion containing a silicon (Si) or a silicon (Si) oxide as a main constituent, and wherein a content of the silicon in the ferromagnetic layer is in a range of 8 to 15 atomic %, wherein a thickness of the ferromagnetic layer is 8-16 nm, wherein a ratio of the thickness of the ferromagnetic layer to the thickness of the exchange energy control layer is 3 to 4.