Phase-change information recording medium, manufacturing method for the same, sputtering target, method for using the phase-change information recording medium and optical recording apparatus

Abstract

It is an object of the present invention to provide a phase-change information recording medium, and the like, which is easy to perform initial crystallization, exhibits good recording sensitivity at a linear velocity as high as 10 double speeds or more with as much capacity as DVD-ROM, is capable of overwrite recording and has good storage reliability. For this purpose, the phase-change information recording medium comprises a substrate and at least a first protective layer, a phase-change recording layer, a second protective layer, and a reflective layer disposed on the substrate in one of this sequence and reverse sequence wherein the phase-change recording layer comprises a composition expressed by SnSbGaGeTe−X(In this regard, X represents at lease one element selected from Ag, Zn, In and Cu. α, β, γ, δ, ε and ζ represent composition ratio (atomic percent) of each element and are expressed as 5≦α≦25, 40≦β≦91, 2≦γ≦20, 2≦δ≦20, 0≦ε≦10, 0≦ζ≦10 and α+β+γ+δ+ε+ζ=100).