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 a material represented by InxSnyTez. 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 alloy with a composition of InxSbyTez, wherein x, y and z are atom percents in the ranges of 48 <= x <= 52, 14.7 <= y <= 18.7, and 31.3 <=z <= 35.3. The recording layer 13 is in a 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. |