MANUFACTURING METHOD FOR MAGNETIC RECORDING MEDIUM

THE PRESENT INVENTION RELATES TO A MANUFACTURING METHOD FOR A MAGNETIC RECORDING MEDIUM (1), AND PROVIDES A MANUFACTURING METHOD FOR OBTAINING A PROTECTIVE LAYER (4) WHICH HAS BOTH GOOD CORROSION RESISTANCE AND GOOD LUBRICANT ADHESIVENESS. THE PRESENT INVENTION IS A MANUFACTURING METHOD FOR A MAGNETIC RECORDING MEDIUM (1) WHICH INCLUDES A MAGNETIC LAYER (3), A LOWER PROTECTIVE LAYER (41), AN UPPER PROTECTIVE LAYER (42) AND A LUBRICATING LAYER (5) ON A SUBSTRATE (2), AND IN WHICH THE TOTAL FILM THICKNESS OF THE LOWER PROTECTIVE LAYER AND THE UPPER PROTECTIVE LAYER IS 2.5 NM OR LESS, THIS METHOD SEQUENTIALLY INCLUDING: 1) A STEP OF DEPOSITING THE LOWER PROTECTIVE LAYER (121); 2) A STEP OF PERFORMING OXYGEN PLASMA TREATMENT (122) ON THE LOWER PROTECTIVE LAYER; 3) A STEP OF DEPOSITING THE UPPER PROTECTIVE LAYER (123); AND 4) A STEP OF PERFORMING NITROGEN PLASMA TREATMENT (124) ON THE UPPER PROTECTIVE LAYER. IT IS PREFERABLE THAT THE LOWER PROTECTIVE LAYER AND THE UPPER PROTECTIVE LAYER ARE FORMED OF A CARBON-BASED MATERIAL, AND IT IS FURTHER MORE PREFERABLE THAT THE LOWER PROTECTIVE LAYER AND THE UPPER PROTECTIVE LAYER ARE FORMED OF DIAMOND-LIKE CARBON. MOREOVER, IT IS PREFERABLE THAT THE CONTACT ANGLE OF THE LOWER PROTECTIVE LAYER WITH RESPECT TO WATER IN THE ATMOSPHERE IS 25" OR LESS.