Patent ID: 7601481
Filing Date: 2009-10-13
Classification: G11B,Y10S

Abstract:
1. A multilayer phase-change information recording medium comprising: a substrate, and N layers of information layer, in which N represents an integral number of 2 or more, wherein each of information layers comprises at least a recording layer in which information is recorded by laser beam irradiation to induce a phase change between crystalline phase and amorphous phase, wherein when the information layers are disposed so that a first information layer, a second information layer, . . . , and N information layer are disposed in this sequence from the laser beam irradiation side, at least one information layer other than the N information layer comprises wherein the thermal diffusion layer comprises at least indium (In), oxygen (O), and at least any one of titanium (Ti) and zirconia (Zr), and wherein the atomic ratio of indium (In) to all the metal elements in the thermal diffusion layer, In/all the metal elements, is 0.75 to 0.85.