| 摘要 |
PURPOSE:To enable overwriting by providing sequentially a first amorphous silicon layer, a recording layer, a second amorphous silicon layer and a metallic layer on a substrate, and forming the recording layer of an alloy with a specified composition. CONSTITUTION:A substrate 11 is formed from a material being transparent and showing little change with time, for example, a glass or polycarbonate. An a-Si layer 12, a recording layer 13, an a-Si layer 14, a metallic layer 15 and a protective layer 16 are provided on the substrate 11. The recording layer 13 is formed of an In-Sb-Te alloy capable of showing a phase change between a crystalline phase and an amorphous phase, the alloy having an enthalpy of mixing in liquid phase of less than -5,000J/mol. The recording layer 13 is in the crystalline phase in an initialized state, and an amorphous record mark 19 is formed upon irradiation with a laser beam 18 under predetermined conditions. The a-Si layers 12, 14 heat-insulate the recording layer 13, whereas the metallic layer 15 rapidly cools the irradiated part, and the protective layer 16 prevents generation of flaws or the like. |
