| 摘要 |
PURPOSE:To form a high-quality aluminum-alloy reflecting film which is free from pin holes and oxide films by forming the reflecting layer under a prescribed condition by a sputtering method by using a material which is prepared by adding at least titanium to aluminum. CONSTITUTION:A protective layer 3, recording layer 4, protective layer 5, reflecting layer 6, and protective layer 7 are successively formed on one surface of the optical disk substrate 2 of a phase-changing type optical disk 1. Of the layers, the layer 6 increases reproduced signals by optically enhancing optical changes in the layer 4 and, at the same time, has a layer 4 cooling effect. In addition, a material prepared by adding at least titanium to aluminum is used for forming the layer 4 and, when the layer 6 is formed by a sputtering method, a target which becomes the raw material of the material is sputtered after setting a vacuum of <=5/1,000,000Torr in a sputtering chamber. Since the sputtering atmosphere can be maintained in a clean state and a harmful gas which becomes an impurity can be eliminated, a high-quality reflecting layer 6 which is free from pinholes and oxide films can be obtained. |
