| 摘要 |
PURPOSE:To maintain the writing characteristic of the titled medium for a long period and to preserve the written information by forming a barrier layer consisting of the thermal oxidation product of a recording film between the recording films. CONSTITUTION:A heater is composed of a belt 15 for conveying the deposit for a metallic thin film 13a above a substrate 11, a heat generating zone 16 for irradiating IR rays on the thin film 13a and a cooling zone 17 for cooling the thin film 13a. The surface of the thin film 13a is thermally oxidized while regulating the thickness of the thermally oxidized film by changing the velocity of the belt 15 and the temp. of the heat generating zone 16 to form a barrier layer 13b. When a laser beam is irradiated on the optical disk having the layer 13b from the substrate 11 side, a single layer having different reflectivity is formed at the irradiated site and the information is read by utilizing the reflectivity. While a laser beam is not irradiated, the diffusion of the thin film 13a and a semiconductor thin film 13c is blocked by the layer 13b, hence the life of the optical disk is prolonged and the wiring characteristic can be maintained for a long period. |
