| 摘要 |
PURPOSE:To improve initializing and erasing characteristics by using amorphous silicon layer to form the part of two protective layers sandwiching a recording layer where said protective layers are adjacent to the recording layer and specifying the layer thickness thereof. CONSTITUTION:This recording medium has the substrate 11, the recording layer 13 on which information is recorded and erased by the phase change taking place between different crystal phases when a light beam is projected thereto, the 1st protective layer 12 which is formed between the substrate 11 and the recording layer 13, and the 2nd protective layer 14 which is formed on the recording layer 13. At least the part of the 1st protective layer 12 and the 2nd protective layer 14 where said layers are adjacent to the recording layer 13 is formed of the amorphous silicon layer and the amorphous silicon layer is formed to the layer thickness larger than 100Angstrom and smaller than 2,800Angstrom . Since the amorphous silicon has the thermal diffusivity lower than the thermal diffusivity of SiO2, the layer thereof has the high capacity to retain the temp. of the recording layer. The slow cooling and solidifying of the recording layer at the time of the phase change are possible if the layer thickness is in the above-mentioned range. The initializing and erasing characteristics are thereby improved. |
