| 摘要 |
PURPOSE:To prevent the intrusion of impurities to thin films by forming the thin films by using a sputtering target formed by coating the surface of a backing plate. CONSTITUTION:A 1st protective layer 2 consisting of ZnS-SiO2 is previously formed on a transparent polycarbonate substrate 1 on a disk having a central hole. A recording layer 3 consisting of Ge, Te or Sb, a 2nd protective layer 4 consisting of the same material as the material of the layer 2 and a reflection layer 5 consisting of an Al alloy are formed thereon. A protective layer 6 is adhered thereon. The following target is used in order to prevent the intrusion of the impurities into the films in the formation of the layers 2, 4: The backing plate 21 made of copper is coated with a coating agent 23 and the target 22 is joined onto this plate. The material similar to the material of the target 22 or the material plated with metals, such as Ni, Cr and Au, is used as the material of the coating agent 23. |
