Patent ID: 6775226
Filing Date: 2004-08-10
Classification: G11B

Abstract:
An information recording medium for recording information by changes in at least one of atomic arrangement and electronic state by laser beam irradiation, which comprises at least a substrate having a groove shape with a groove depth dg, and a recording layer having a shape corresponding to the groove shape, and three thin film layers of different compositions comprising a first interference layer, a second interference layer and a first interface layer, successively formed in this order from the laser beam incident side of the recording layer, the thermal conductivity of the first interference layer being lower than that of the second interference layer, the refractive index of the second interference being smaller than that of any of the first interference layer and the recording layer, the first interface layer being provided in contact with the recording layer and between the second interference layer and the recording layer, the second interference layer containing oxygen, a protective layer having a smaller oxygen content than that of the second interference layer being provided between the second interference layer and the first interface layer, and the distance between the first interference layer and the recording layer being less than dg.