| 摘要 |
PROBLEM TO BE SOLVED: To enable high-density recording by forming a phase transition type optical recording layer with Gey (Sbx Te1-x )1-y compsn. and >=15nm and <=30nm thickness and forming an upper protective layer to between >=10nm and <=30nm thickness. SOLUTION: The compsn. of the GeSbTe ternary alloy thin film is obtd. by using a compsn. near Sb70 Te30 eutectic compsn. as the base material and adding Ge as shown in the figure. If the film thickness of the upper protective layer is larger than 30nm, the period when heat in the recording layer reaches a reflection layer increases and the heat radiation effect of the reflection layer is not effectively obtd. Namely, the reflection layer acts as a pump to pump the heat, while the upper protective layer is regarded as a pipe to conduct the heat flow to the pump. If the protective layer is thick, it means the pipe is long. This is not effective although the pump has high performance (although the reflection layer has high thermal conductivity). |
