| 摘要 |
PURPOSE:To enable high-density recording and to provide sufficient weather resistance and head crush resistance, by successively forming a chromium oxide film having <=20nm thickness and an SiO2 film having <=30nm thickness as protective films on a metallic magnetic thin film. CONSTITUTION:A metallic magnetic thin film 2 is formed on a substrate 1, and a chromium oxide film 3 having <=20nm thickness and an SiO2 film 4 having <=30nm thickness are successively formed on the film 2. The film 3 has superior weather resistance, and the film 4 has superior head crush resistance. Since the total thickness of the films 3, 4 is as small as <=50nm, highdensity recording is enabled. For example, an Ni-Co-P film having 50nm thickness is formed on a substrate for a disk by electroless plating and dried. The substrate is placed in a sputtering chamber, and RF sputtering is carried out by using a chromium plate having 100mm. diameter as a target electrode in an oxygen atmosphere under 1-5Pa pressure for a time corresponding to the desired thickness. An SiO2 film having the desired thickness is then formed by sputtering using an SiO2 plate as a target in an Ar atmosphere. |
