MULTI-LAYER PHASE VARIATION TYPE INFORMATION RECORDING MEDIUM, AND ITS RECORDING REPRODUCING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a multi-layer phase variation type information recording medium which has excellent recording characteristics in blue wave lengths, and is equipped with a semi-permeable recording layer being arranged on the front surface side irradiated with a laser beam.;SOLUTION: This multi-layer phase variation type information recording medium has at least two layers of information layers on a base board, and the information layers have at least a recording layer. Also, the information layers are laminated with an interval being optically separable in the direction of the incidence of the same laser beam. The semi-permeable recording layer which performs recording by making the laser beam permeate from among the recording layers of the information layer contains Ge-SnTe and SbTe having a comprosition near the eutectic composition. At the same time, the composition of the semi-permeable recording layer exists in a region surrounded by respective composition points of A((Ge-Sn)₂₉, Sb₃₆, Te₃₅), B((Ge-Sn)₂₅, Sb₃₆, Te₃₉), C((Ge-SN)₁₀, Sb_57.6, Te_32.4), and D((Ge-Sn)₁₀, Sb₆₈, Te₂₂) in the triangular coordinate figure for which respective elements of Ge-Sn, Sb and Te are made the vertexes.;COPYRIGHT: (C)2005,JPO&NCIPI