Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Yoshitaka Sakaue

Eiji Ohno

Noboru Yamada

Rie Kojima

Takashi Nishihara

Ken'ichi Nagata

Kenichi Nagata

Kenichi Nishiuchi

Nobuo Akahira

Kazuhisa Ide

Masahide Yokoyama

Hiroshi Hayata

Hiroyuki Ohta

Naoyasu Miyagawa

Hideo Kusada

Hideki Kitaura

Haruhiko Habuta

Akio Tsuchino

Tomoyasu Takaoka

An information recording medium of the present invention includes N information layers on a substrate (), where N is an integer of 2 or more. Information is recorded/reproduced by irradiating each of the information layers () with a laser beam (). When the N information layers are referred to as a first information layer to an N-th information layer sequentially from the opposite side to a laser beam incident side, the L-th information layer included in the N information layers includes at least a recording layer () capable of undergoing a phase change through laser beam irradiation, a reflective layer (), and a transmittance adjusting layer () in this order from the laser beam incident side, where L is an integer satisfying 2&#x2266;L&#x2266;N. The transmittance adjusting layer () contains Nb, oxygen (O), and at least one element M selected from Ti, Zr, Hf, Y, Cr, Zn, Ga, Co, Bi, In, Ta, and Ce. In the transmittance adjusting layer (), the content of Nb is at least 2.9 atom %.

Information recording medium and method for manufacturing same

An information recording medium,capable of recording information by irradiation of light or applying electrical energy, wherein at least one of first and second dielectric layers, first interface layer and counter-incident side interface layeris formed from a Si&#x2014;In&#x2014;Zr/Hf&#x2014;O-based material containing at least Si, In, M1 (M1 represents at least one element selected from among Zr and Hf) and oxygen (O), with Si content being 1 atomic % or more. This medium has high recording sensitivity when information is recorded thereon, high overwrite cycle-ability and high signal intensity.

Information recording medium and method for manufacturing the same

An information recording medium of the present invention includes recording layersandwhose phase can change by an optical or an electrical system so as to be detectable, and interface layersand, which are in contact with the recording layersand, to serve as oxide layers. The recording layercontains a Ge&#x2014;Bi&#x2014;Te-M material represented by a formula: GeBiTeM(atom %), where M denotes at least one element selected from Al, Ga, In and Mn, and &#x3b1;, &#x3b2; and &#x3b3; satisfy 25&#x2266;&#x3b1;&#x2266;60, 0&#x3c;&#x3b2;&#x2266;18, 35&#x2266;&#x3b3;&#x2266;55, and 82&#x2266;&#x3b1;+&#x3b2;+&#x3b3;&#x3c;100. The interface layersandcontain at least one oxide of the element M contained in the recording layersand

Information recording medium, method and apparatus for manufacturing 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

The optical information recording medium of the present invention includes a plurality of information layers provided on a substrate and an optical separating layer provided between information layer adjacent to each other, and information is recorded or reproduced by irradiation of a laser beam. When an information layer that is provided closest to a laser beam incident side of the plurality of information layers is taken as a first information layer and an optical separating layer provided in contact with the first information layer is taken as a first optical separating layer, then the first information layer comprises a recording layer, a transmittance adjusting layer that adjusts a transmittance of the first information layer, and a low refractive index layer provided between the transmittance adjusting layer and the first optical separating layer.

Optical information recording medium and manufacturing method thereof

A method for appropriately performing initialization of an optical information recording medium is provided, in which an initialization process is prevented from stopping so that yield from manufacturing the optical information recording medium is improved. In the initialization of an information layer with a burst cutting area (hereinafter referred to as 'BCA'), at least one of the initialization conditions including a laser power, a linear speed, and a focal point of the laser beam for the information layer is changed between the BCA region and a data area that is an area for recording and reproducing information. In the initialization of an information layer without the BCA, at least one of the initialization conditions including a laser power, a linear speed, a focal point of the laser beam for the information layer and a feed pitch is changed between the area corresponding to the BCA and the area corresponding to the data area.

Optical information recording medium and method for manufacturing the medium

A disk with an Ag reflective layer, a recording layer including elements Sb and Te, and a dielectric layer including S provided between the reflective layer and the recording layer has the problems of corrosion of the Ag reflective layer, decline of the signal quality due to insufficient heat releasing ability, and exfoliation between the layers. (1) A phase-change optical disk includes, on a transparent substrate, a recording layer in which an optically detectable reversible change between an amorphous phase and a crystalline phase can be caused by irradiation with an energy beam, a reflective layer, and a dielectric layer arranged between the recording layer and the reflective layer, wherein the main component of the dielectric layer is an oxide or a nitrooxide of Ta. (2) Between the recording layer and the dielectric layer, a layer including a nitride, an oxide, a carbide or nitrooxide of an element &#x3b1; (wherein &#x3b1; is at least one element selected from Sn, In, Zr, Si, Cr, Al, V, Nb, Mo, W, Ti, Mg and Ge) is provided.

Optical information recording medium, method for manufacturing the same and recording/reproduction method

When initializing first and second information layers on a phase-change optical disk of the one-side multilayered configuration, a mistake occurs depending on thin film configuration of first and second information layers. The phase-change optical disk having a plurality of information layers having at least a recording layer of generating optically detectable reversible change between an amorphous phase and a crystalline phase on a transparent substrate by irradiation of an energy beam and having an optical separation layer formed between the information layers, wherein initialization start positions of crystallizing said plurality of information layers vary by irradiating a laser beam thereon.

Optical information recording medium

An optical information recording medium of the invention has at least two information layers. A first information layer () disposed at the front side (viewed from a laser incident side) includes at least a reflection layer (), a recording layer () disposed at the laser incident side with respect to the reflection layer (), for generating a reversible change between an amorphous phase and a crystalline phase that can be detected optically by applying a laser beam, and a dielectric layer () disposed between the reflection layer () and the recording layer (). The dielectric layer () contains at least Zr, Si and Cr, a ratio of Zr, Si and Cr of the dielectric layer () at the reflection layer side is expressed as Zr:Si:Cr=p:q:r (p+q+r=100), a ratio of Zr, Si and Cr of the dielectric layer () in the vicinity of the interface at the recording layer side is expressed as Zr:Si:Cr=s:t:u (s+t+u=100), and r&#x3c;u or t&#x3c;q.

An optical information recording medium of the present invention includes at least one information layer. The information layer includes a first protective film, a first interface film, a recording film having the optical characteristics that are changed reversibly by laser beam irradiation, a second interface film, a second protective film, and a reflective film, present in the indicated order from the laser beam incident side. The first interface film includes an oxide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Si. The second interface film includes carbon or a carbide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Si.

Optical information recording medium and manufacturing method and recording/reproducing method for the same

An optical information recording medium that is a phase-change type optical disk includes, on a transparent substrate having a land and a groove, a phase-change type recording layer in which an optically detectable reversible change occurs between an amorphous phase and a crystalline phase by irradiation with an energy beam, wherein dielectric layers are provided so as to be in contact with at least one side of the phase-change type recording layer, the phase-change type recording layer contains at least one selected from the group consisting of Te, Se, Sb, In, Ge, and Ag as a main component, aid the dielectric layers contain, as main components thereof, at least one selected from the group consisting of Ge and Si, and N. The dielectric layers contain an element &bgr; (where &bgr; is at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Cu, Ag, Au, Zn, and Cd) or an element &ggr; (where &ggr; is at least one element selected from the group consisting of Sb, Te, Se, Sn, Ga, and In), and the phase-change type recording layer contains an element &agr; (where &agr; is at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Cu, Ag, Au, Zn, and Cd). Thus, the optical information recording medium of the present invention exhibits satisfactory cycle characteristics, in which movement of a material in a phase-change type recording layer is suppressed even with a large number of repetitions of so-called land & groove recording.

The present invention is to provide a method for manufacturing the PCE optical information recording disk under control of not only the crystallization velocity but also the complex index of refraction and thus the reflectance on the disk surface. The PCE optical information recording disk is suitable to be used under the constant angular velocity (the constant rotational numbers wherein the disk has a characteristic that the crystallization velocity is designed to become faster from inside area of the disk to outside area in the radical direction thereof under control of not only the crystallization velocity but also the complex index of refraction and thus the reflectance on the disk surface. In the case of mass production and high film formation to be required, the present invention provides an effective method for manufacturing the optical disk by means of sputtering from at least two targets at the same time in a manner that the crystallization velocity is increased in a radial direction from inside area to outside area in the disk.

Optical recording disk and method for manufacturing the same

A method for manufacturing an optical information recording medium having an excellent mechanical strength, thermal stability, and improved overwrite cycle property can be provided by forming the dielectric layer by using a mixed target comprising ZnS and SiO.sub.2 in an atmosphere comprising rare gas and at least oxygen at the side where the dielectric layer does not contact to the recording layer. The optical information recording medium is manufactured by using the substrate, the recording layer comprising a material that varies reversibly between the optically identifiable states by an irradiation of a laser beam, and the dielectric layer at least one side of which has a two-layered structure at the upper and lower sides of the recording layer. At least one of the dielectric layers that does not contact to the recording layer is formed by using a mixed target comprising ZnS and SiO.sub.2 in a mixed atmosphere comprising rare gas and oxygen.

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Osaka, Japan

Yoshitaka Sakaue