Patent ID: 7081268

Claim:
A method of manufacturing a magnetic recording medium, comprising sequential steps of: (a) providing an apparatus for manufacturing said medium; (b) supplying said apparatus with a substrate for said medium; (c) forming a magnetic recording layer on said substrate in a first portion of said apparatus, wherein the magnetic recording layer is selected from the group consisting of: (1) a Co-based alloy, Cr-rich grain boundary magnetic layer comprising a CoCrPtX alloy, where X=at least one element selected from the group consisting of Ta, B, Mo, V, Nb, W, Zr, Re, Ru, Cu, Ag, Hf, Ir, and Y, and wherein Co-containing grains with hcp lattice structure are segregated by Cr-rich grain boundaries, (2) a granular magnetic layer comprising a CoPtX alloy, where X=at least one material selected from the group consisting of Cr, Ta, B, Mo, V, Nb, W, Zr, Re, Ru, Cu, Ag, Hf, Ir, Y, SiO 2 , SiO, Si 3 N 4 , Al 2 O 3 , AlN, TiO, TiO 2 , TiO x , TiN, TiC, Ta 2 O 3 , NiO, and CoO, and wherein Co-containing grains with hcp lattice structure are segregated by oxide, nitride, or carbide grain boundaries, (3) a superlattice layer comprising a multi-layer (CoX/Pd) n or (CoX/Pt) n structure, where n is an integer from about 10 to about 25 and X is an element selected from the group consisting of Cr, Ta, B, Mo, Pt, W, and Fe, and (4) an L1 0 ferromagnetic metal alloy layer comprising a FePt or CoPt alloy; (d) treating said magnetic recording layer, as deposited on said substrate in step (c), with oxygen gas in a second portion of said apparatus at a sub-atmospheric pressure and for an interval sufficient to provide the resultant medium with at least one of the following, relative to a similar medium manufactured by a similar method but wherein the oxygen treatment of step (d) is not performed: (i) a more negative nucleation field (H n ); (ii) increased remanent squareness (S r ); (iii) increased signal-to-medium noise ratio (SMNR); (iv) narrower switching field distribution (SFD); and (v) decreased thermal decay rate; and (e) forming a protective overcoat layer on said oxygen-treated magnetic recording layer in a third portion of said apparatus.