Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Akio Tsuchino

Rie Kojima

Noboru Yamada

Takashi Nishihara

Hideo Kusada

Kenichi Nishiuchi

Yoshitaka Sakaue

Kazuki Aita

Toshiyuki Matunaga

An information recording medium and a method for producing the same according to the present disclosure are configured to have an information layer in which a larger amount of light for reproduction can be obtained, so that the medium is suitable for recording information at high recording density and is useful for a multi-layer optical disc that records a large amount of contents.

Information storage medium having multiple recording layers

An information recording medium according to the present disclosure is an information recording medium of a write-once-read-many type and records or reproduces information when irradiated with laser light. The information recording medium includes: a substrate; a plurality of information layers at least one information layer of which includes a recording film that is a W&#x2014;O-based recording film comprising at least tungsten (W) and oxygen (O); and a dielectric film A in contact with the W&#x2014;O-based recording film, the dielectric film A comprising at least 30 mol % tin oxide.

Information recording medium and method for manufacturing information recording medium

An information recording medium including three or more information layers, wherein: at least one information layer includes a recording layer and a nucleation layer; the recording layer contains a material that is represented by formula (1) [(GeTe)(InTe)]Sb(mol %) with x satisfying 0.8&#x2266;x&#x3c;1.0 and y satisfying 95&#x2266;y&#x3c;100; the nucleation layer contains a material that is represented by formula (2) (GeTe)(BiTe)(mol %) with z satisfying 10&#x2266;z&#x2266;71; and the nucleation layer is in contact with the recording layer. This information recording medium is capable of achieving sufficient signal amplitude even in cases where a small recording mark is formed, and is also capable of stably maintaining a small recording mark.

Information recording medium and method for producing same

An optical information recording medium including three or more information layers, wherein at least one information layer provided on the light incident side is an information layer which enables information to be overwritten and includes a recording film, a transmittance adjusting film of a dielectric containing Bi, Ti and O, and an isolation film in this order from a light incident side; and the isolation film is provided between and adjacent to the transmittance adjusting film and an intermediate separation layer which separate the information layer from another information layer on the side opposite to the light incident side; and the isolation film has an optical constant at a wavelength of 405 nm such that a refractive index is 1.8 or less and an extinction coefficient is 0.05 or less. This information recording medium prevents the repeated overwriting characteristics in a sever environment from being deteriorated.

Information recording medium and method for manufacturing the same

An information recording medium () of the present invention is an information recording medium with respect to which information can be recorded or reproduced by irradiation with an optical beam (). The information recording medium () includes a second interface layer (), a recording layer () and a first interface layer () in this order from the optical beam () incident side. The first interface layer () and the second interface layer () are disposed in contact with the recording layer (). The second interface layer () contains M1 (where M1 is at least one element selected from Nb, Y, Dy, Ti, Si and Al), Cr and oxygen (O). The first interface layer () contains M2 (where M2 is at least one element selected from Nb, Y, Dy, Ti, Si, Al, Zr and Hf), Cr and oxygen (O). The first interface layer () and the second interface layer () each contain Cr in a range of 50 mol % or less in terms of the oxide (CrO).

Information recording medium

An optical information recording medium () of the present invention includes an information layer () that allows information to be recorded thereon and reproduced therefrom by irradiation with a laser beam (). The information layer () includes a reflective layer (), a first dielectric layer (), a recording layer () capable of undergoing a phase change by the irradiation with the laser beam () and a second dielectric layer () formed in this order from a side opposite to a laser beam incident side. The recording layer () contains Ge, Sb and Te. When Ge, Sb and Te contained in the recording layer () are represented by GeSbTein atomic number ratio, x, y, and z satisfy 0.39&#x2266;x&#x2266;0.48, 0.02&#x2266;y&#x3c;0.11, 0.40&#x2266;z&#x3c;0.56, and x+y+z=1. The recording layer () has a thickness of at least 10 nm but not more than 15 nm. In the case where a ratio of an amount of reflected light of the laser beam () from the information layer () to an amount of the laser beam () incident on the information layer () is denoted as R (%), the R when the recording layer () is in a crystalline state is denoted as Rc (%), and the R when the recording layer () is in an amorphous state is denoted as Ra (%), Rc and Ra satisfy 6.0&#x2266;Rc/Ra&#x2266;12.0 and 1.0&#x2266;Rc&#x2266;3.0.

Optical information recording medium and recording/reproducing method therefor

The information recording medium () of the present invention includes a recording film (). The information recording medium () allows information to be recorded and reproduced on and from the information recording medium by irradiation of the recording film () with a laser beam (). The information recording medium () of the present invention further includes a mixed dielectric film (the second dielectric film) disposed on the laser beam () incident side with respect to the recording film (). The mixed dielectric film contains a mixed dielectric material consisting of Zn sulfide, Si oxide and an oxide X (where the oxide X is an oxide of at least one element selected from Ti, Nb, Ta and Ce).

Information recording medium and method for producing the same

An information recording medium () of the present invention is an information recording medium allowing information to be recorded thereon by irradiation with a laser beam or by application of electrical energy. The information recording medium () includes a recording layer () capable of undergoing a phase change by the irradiation with the laser beam or by the application of the electrical energy. The recording layer () contains Sb, Te, Ge, and C, and a content of Te in the recording layer () is at least 8 atom % but not more than 25 atom %.

Information recording medium and method for producing same, and sputtering target

According to the present invention, a recording film is partially initialized using a first light beam (A) having a wavelength for initialization, focus adjustment is performed using a second light beam (B) having a wavelength corresponding to a wavelength for recording and reproducing information on and from an information recording medium, and then the recording film is initialized using the first light beam (A), thereby it is possible to securely initialize recording films of all information layers of a multilayer information recording medium.

Initialization method for information recording medium, initialization apparatus for information recording medium, and information recording medium

An information recording medium of the present invention includes a recording layer whose phase changes by irradiation with a laser beam or application of current. The recording layer contains, as its main component, a composite composed of Ge and Sb that are essential components, and Te that is an optional component. The composite has a composition within a region enclosed by: point (a) (35, 65, 0), point (b) (36.9, 60, 3.1), point (c) (3.2, 60, 36.8), and point (d) (5, 95, 0) in terms of a coordinate (Ge, Sb, Te)=(x, y, z) on the triangular coordinate shown in FIG., where point (b) corresponds to a point at Sb=60 on GeTe&#x2014;GeSb, point (c) corresponds to a point at Sb=60 on Te&#x2014;GeSb, and the region includes lines extending between point (a) and point (b), point (b) and point (c), point (c) and point (d), and point (d) and point (a).

Information recording medium, target and method for manufacturing of information recording medium using the same

In each of at least two information layers () which constitute a information recording medium having a plurality of information layers on its one side, the compositions of the recording layer () and the dielectric layers () adjacent to the recording layer () in one information layer () are common to the compositions of the corresponding layers () in the other information layer, so that the recording layers () and the dielectric layers () and () in the two information layers () can be formed in common sputtering film-forming chambers without the replacement of targets, which makes it possible to produce a multi-layer single-sided recording medium with a decreased time loss in the production process.

Information recording medium and its production process

There is provided a dielectric material containing no sulfur (S), and there is provided an information recording medium that affords high signal quality and excellent recording sensitivity and repeated rewrite characteristics, even though no interface layer is provided between a reflective layer and a dielectric layer. To this end, the present invention is an information recording medium that is equipped with at least a recording layer and undergoes phase change when the recording layer is irradiated with a laser beam or when current is applied, comprising an oxide-fluoride dielectric layer that includes indium (In), an element M1 (where M1 is at least one element selected from among Zr, Hf, Y, Ti, Nb, Ta, Cr, Ga, and Si), oxygen (O), an element M2 (where M2 is at least one element selected from among La, Ce, Pr, Nd, Gd, Tb, Dy, Ho, Er, Yb, Mg, Ca, and Sr), and fluorine (F).

Information recording medium and method for manufacturing thereof

An information recording medium with high recording sensitivity, superior repeat overwriting capability and favorable signal storage stability during information recording is offered. For this purpose, an information recording medium comprises one or more information layers that include a phase-change recording layer, wherein at least one of the information layers includes, a Cr-containing layer containing Cr and O that contact with one side of a surface of the recording layer, and an In-containing layer containing In and O that contact with the other side of the surface of the recording layer.

Information recording medium and method of manufacturing the same

An information recording medium with high recording sensitivity and superior repeat overwriting capability. The information recording medium () comprising at least recording layer () recording and/or reproducing information through irradiation with a laser beam or application of an electric current, and second dielectric layer () on substrate (), wherein the second dielectric layer () comprises M1 (provided that M1 is at least one element selected from Sc, Y, La, Gd, Dy and Yb) and O.

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Osaka, Japan

Akio Tsuchino