| 摘要 |
PROBLEM TO BE SOLVED: To increase the recording capacity while suppressing deterioration in jitters or decrease in the modulation degree and keeping enough recording characteristics. SOLUTION: A first dielectric film 3, phase transition recording film 4, second dielectric film 5, reflection film 6 and protective film 7 are successively formed on a disk substrate 2 having lands and grooves on one principal face 2a and wobbles. The recording film 4 consists of a GeInSbTe alloy and the reflection film 6 consists of a AgPdCu alloy or AlCu alloy. The composition ratio of the GeInSbTe alloy is controlled to 1 to 8 wt.% Ge, 2 to 6 wt.% In, 2.2 to 3.0 ratio of Sb/Te, and the composition of the AgPdCu alloy is controlled to 0.9 to 1.5 wt.% of Pd, 0.9 to 1.1 wt.% of Cu, and the content of the Cu in the AlCu alloy is controlled to <=1.5 wt.%. The grooves are formed to 35 to 45 nm groove depth and 0.35 to 0.50 μm groove width. The first dielectric film 3, recording film 4, second dielectric film 5 and reflection film 6 are formed to 75 to 95 nm, 12 to 20 nm, 16 to 28 nm and 80 to 160 nm thickness, respectively. |
