摘要 |
PURPOSE:To obtain a recording medium superior in durability, by exposing a base material to the plasma of N2 or O2 to nitride or oxidize the surface after a ferromagnetic metal thin film layer and/or a metallic thin film layer consisting of Al or the like are formed on the base material. CONSTITUTION:A ferromagnetic metallic thin film layer and/or a metallic thin film layer consisting of one or more among Al, Ti, Cr, and Si are formed on a base material. This ferromagnetic metallic thin film layer or the metallic thin film layer on this thin film layer is exposed to the plasma of gaseous N2 or O2 generated by AC electrodes 5 and 6 to nitride or oxidize the surface of the ferromagnetic metallic thin film layer or the metallic thin film layer. For example, a base material 4 where the ferromagnetic metal thin film layer is formed is set to a substrate 3 in a vacuum tank 1 and is exposed to gas generated across ring-shaped AC electrodes 5 and 6, which are arranged in both sides of the substrate 3, to nitride or oxidize the surface. |