Other

Hitachi Maxell, Limited

Hitachi Maxwell, Ltd.

Yoshihiro Ikari

Makoto Miyamoto

Reiji Tamura

Tamotsu Fuchioka

Motoyasu Terao

Yumiko Anzai

Yasushi Miyauchi

Junko Ushiyama

Keikichi Ando

Makoto Iimura

Hitoshi Watanabe

Akemi Hirotsune

Tetsuya Nishida

Nobuhiro Tokushuku

Keikichi Andoo

Yukio Fukui

Takehiko Yorozu

Naoki Kitagaki

Toshiaki Taii

Norio Ota

Akira Kashiwakura

Yutaka Watanabe

Mayumi Kurokawa

Sonoko Onodera

In an information recording medium, a Bi&#x2014;Ge&#x2014;Te material is adopted as a phase-change recording layer material. A C&#x2014;Ta&#x2014;O material is used for at least any one of first and second boundary layers which are in contact with a recording layer.

Information recording medium

A phase-change optical recording medium capable of performing recording and reproduction at a high speed is provided, in which a reproduced signal output is not only sufficiently large but the phase-change optical recording medium also has excellent repeated rewriting performance. An interface layer, which is composed of a Ge&#x2014;Si&#x2014;N-based material, is formed on at least a surface of one side of a recording layerof the phase-change optical recording medium. Accordingly, even when a phase-change material having a high melting point, for example, a Bi&#x2014;Ge&#x2014;Te-based phase-change material is used for the recording layer, it is possible to provide the phase-change optical recording medium in which the reproduced signal output is sufficiently large and the repeated rewriting performance is excellent.

Phase-change optical recording medium

In an optical disk for high density recording, for preventing the deformation of recording tracks caused by stress which may develop between the substrate and the recording stacked film formed thereon, a stress-compensation layer having a metal element such as Ti or Cr as a main component is provided. The stress-compensation layer undergoes contraction (tensile stress) to compensate for compression stress which develops in the stacked film during cooling after the thermal expansion of the substrate surface that occurs at the end of film formation. The stress-compensation layer has a pillar-like structure which, starting from the lower face, reaches the upper face of the film.

Information recording medium and method for manufacturing information recording medium

A high-density information recording medium free from lowering the reflectance by over-write of a large number of times and exfoliation defect in a structure for suppressing cross-erase. This medium includes, over a substrate having a groove shape, a recording layer, and three-layered thin films of a first interference layer, a second interference layer and an interface layer having mutually different compositions and disposed on a laser beam incidence side of the recording layer in order named from the laser beam incidence side. The first interference layer has a smaller refractive index and a larger thermal conductivity than the second interference layer, the interface layer is interposed between the second interference layer and the recording layer, and a distance between the first interference layer and the recording layer is greater than at least a groove depth.

An information recording medium having recording, reproducing, and rewriting characteristics better than those of prior art media. The media has a recording layer made of a material represented by the following formula: Ge Sb Te M , wherein 0.13&lE;x&lE;0.22, 0.20&lE;y&lE;0.32, 0.53&lE;z&lE;0.60, 0&lE;w&lE;0.06, x&plus;y&plus;z&equals;1, and M is any one of Na, Mg, Al, P, S, Cl, L, Ca, Sc, Zn, Ga, As, Se, Br, Rb, Sr, Y, Zr, Nb, Ru, Rh, Cd, In, Sn, I, Cs, Ba, La, Hf, Ta, Re, Os, Ir, Hg, Tl, Pb, Th, U, Ag, Cr, W, Mo, Pt, Co, Ni, Pd, Si, Au, Cu, V, Mn, Fe, Ti and Bi.

Disclosed is a phase-change optical recording medium which has a reflectance and a signal modulation conformed to the CD standard, and which is usable for recording at the same linear velocity as the reproducing velocity specified in the CD standard. The phase-change optical recording medium comprises a metallic layer, a first protective layer, a recording layer, a second protective layer, and a reflecting layer on a substrate, in which recording is performed through change from a crystalline state to an amorphous state in the recording layer. The recording layer comprises a recording material of a Ge--Te--Sb--Se system, and the recording layer has an average composition in a direction of thickness which satisfies the following relations as represented by atomic %:

Optical recording medium

Growing community of inventors

Moriya, Japan

Yoshihiro Ikari