Tdk Corporation

Masanori Kosuda

Hiroshi Shingai

Hajime Utsunomiya

Tatsuya Kato

Jiro Yoshinari

Hiroyasu Inoue

Hideki Hirata

Masahito Furukawa

Kenji Uchiyama

Hiroshi Takasaki

Saori Takeda

Takuya Tsukagoshi

Takashi Kikukawa

Junji Tominaga

Masahiro Mori

Isamu Kuribayashi

Shirou Ootsuki

Shinji Miyazaki

Hideki Ishizaki

Masaki Sobu

Hiroshi Chihara

Yasuhiro Takagi

Ryo Inaba

Yuji Sezai

Yoshihisa Tamagawa

Yasunori Harada

Jajime Utsunomiya

Hiroshi Shinngai

The present invention relates to a dielectric element such as a thin-film capacitor including a dielectric film. The dielectric film contains a main component represented by the general formula (BaCa)(TiZr)Owherein 0&#x3c;x&#x2264;0.500, 0&#x3c;y&#x2264;0.350, and 0.900&#x2264;z&#x2264;0.995. The dielectric film includes a layer containing columnar crystal grains and a layer containing spherical crystal grains, and contains as a sub-component at least one of divalent metal elements and trivalent metal elements.

Dielectric film and dielectric element

A thin-film dielectric having a higher dielectric constant than usual ones and not requiring a special single crystal substrate, and a large-capacity thin-film capacitor element using the thin-film dielectric, in which a BaTiO-based perovskite solid solution and a KNbO-based perovskite solid solution are alternately formed to form a crystal structure gradient region where a lattice constant continuously changes at the interface, and thus crystal lattice strain occurs, thereby permitting the production of a thin-film dielectric having a high dielectric constant; also, a large-capacity thin-film capacitor element can be produced by using the thin-film dielectric of the present invention.

Thin-film dielectric and thin-film capacitor element

A dielectric film contains as a main component a dielectric composition represented by the general formula (BaCa)(TiZr)Owherein 0.001&#x2266;x&#x2266;0.400, 0.001&#x2266;y&#x2266;0.400, and 0.900&#x2266;z&#x3c;0.995. In an X-ray diffraction pattern of the dielectric composition, the dielectric composition has the relation 0.00&#xb0;&#x2266;2&#x3b8;&#x2212;2&#x3b8;&#x3c;0.20&#xb0; between (001) plane diffraction peak position 2&#x3b8;of a tetragonal structure represented by the general formula and (100) plane diffraction peak position 2&#x3b8;of a cubic structure represented by the general formula.

A next-generation optical recording medium has two or more information layers which include a translucent information layer. The translucent information layer has a recording film and an interface layer, provided adjacent to the recording film on the side of the light incident surface. The recording film is made of a phase change material having SbTeGeelements and elemental ratios. Y satisfies 5&#x2266;y&#x2266;15 and z satisfies 5&#x2266;z&#x2266;15. When In having an elemental ratio of a is further added and x+y+z+a=100 holds, a satisfies 4&#x2266;a&#x2266;15. The interface layer comprises of ZrO&#x2014;CrOfilm thickness of which is in a range of from 2 nm to 10 nm. When ZrO:CrO&#x2550;C:D (mol %), the compositional ratios ZrOand CrOin the ZrO&#x2014;CrOfilm, holds, the C satisfies 20&#x2266;C&#x2266;90, and the D satisfies 10&#x2266;D&#x2266;80, and the C and the D satisfy C+D=100. The ZrOis stabilized ZrOwhich contains YO, when ZrO:YO=(100&#x2212;X):X (mol %), the compositional ratios ZrOand YOin the stabilized ZrO, holds, the X satisfies 2&#x2266;X&#x2266;10.

Optical recording medium and recording film material

An optical recording medium is provided which includes two or more information layers in which an Sb-based eutectic material is used as the material for a recording film of a translucent information layer. There is also provided a recording film material for the optical recording medium. The translucent information layer is configured to include a recording film formed of a phase change material SbGeIncontaining Sb, Ge, and In in an atomic ratio of x:y:z, where 5&#x2266;y&#x2266;15 and 4&#x2266;z&#x2266;15 are satisfied. The recording film further includes Te in an atomic ratio of a, provided that x+y+z+a=100 and 4&#x2266;a&#x2266;15 are satisfied. An interface layer formed of a ZrO&#x2014;CrOfilm having a thickness of 2 nm or more and 10 nm or less is provided on the laser beam incident side of the recording film. When the compositional ratio of the ZrO&#x2014;CrOfilm is given by ZrO:CrO=B:C (mol %), 20&#x2266;B&#x2266;90, 10&#x2266;C&#x2266;80, and B+C=100 are satisfied.

A rewritable phase-change optical recording medium is provided, which includes a substrate, a first information layer, a spacer layer, a second information layer, and a cover layer. The second information layer includes a recording film containing Sb as a main component and V or V and In as second components. When an amorphous mark formed in the recording film is irradiated with a reproduction beam, crystallization of the amorphous mark occurs only in a central portion in the width direction of the amorphous mark. The width direction is orthogonal to the scanning direction of the laser beam. The recording film is formed of a material that exhibits a change in degree of modulation of 5% or less when recorded information is repeatedly reproduced. The change in degree of modulation is a change from when the number of times of reproduction is 100,000 to when it is 400,000.

Rewritable phase-change optical recording medium

It is an object of the present invention to provide a method for recording information in an optical recording medium with a good direct overwriting characteristic. The method for recording information in an optical recording medium according to the present invention forms record marks in a recording layer containing a phase change material by modulating the power of a laser beam between a plurality of power levels including a recording power Pw, an erasing power Pe and ground power Pb. The erasing power Pe is set to a level within a region where a reflection coefficient of a region between neighboring record marks approaches a reflection coefficient of the record mark as the erasing power Pe increases. As a result, a good overwriting characteristic can be obtained when data are recorded at a high linear velocity.

Medium and method for providing a desirable direct overwriting characteristic for optical data recorded at different linear recording velocities

A vacuum processing apparatusis provided with a bypass linefor causing a vacuum transfer chamberand a load-lock chamberto communicate with each other, and a bypass opening and shutting valvefor opening and shutting the corresponding bypass line, wherein by opening the bypass opening and shutting valve, a pressure-reduced state at the vacuum transfer chamberside can be shifted to the load-lock chamberside, and the pressure reduction of the load-lock chambercan be carried out in a short time.

Vacuum processing apparatus and method for producing an object to be processed

An optical recording medium comprising a substrate, at least one dielectric layer and a phase change type recording layer. In overwriting, the recording medium should satisfy the condition V.sub.OW /V.sub.OP &lt;1, preferably 0.5.ltoreq.V.sub.OW /V.sub.OP &lt;0.95, where V.sub.OP is the optimum linear velocity and V.sub.OW is a linear velocity for overwriting. This enables the erasability of recorded marks on the medium to be at least 26 dB after the recording medium with the recorded marks has been stored for at least 100 hours at 60 to 80.degree. C.

Phase change optical recording medium, method of overwriting same and

The invention provides a method of fabricating an optical recording medium comprising a phase change type recording layer containing at least one element selected from In, Ag, Te and Sb. The recording layer is formed by a sputtering technique wherein sputtering is carried out while an inert gas and an oxygen gas are introduced in a vacuum chamber in a sputtering system, so that the number of overwritable cycles can be increased by simple means.

Optical recording medium and fabrication method therefor

A phase change type optical recording medium of Ge--Sb--Te system wherein number of overwritable operation has been increased is provided. The optical recording medium has a substrate and a recording layer of phase change type on the substrate, and the recording layer contains Ge, Sb and Te as its main elements, and at least one of Ag and Au in total content of 0.2 to less than 2.5 at % (excluding 2.5 at %).

Optical recording medium

An optical recording medium of phase change type which exhibits an increased number of overwritable operations is provided. The optical recording medium comprises a substrate, and a first dielectric layer, a recording layer, a second dielectric layer, and a metal reflective layer disposed on the substrate in this order, and the first dielectric layer comprises a dielectric layer 1a on the side of the substrate and a dielectric layer 1b in contact with the recording layer. The dielectric layer 1a comprises ZnS--SiO.sub.2, and the dielectric layer 1b comprises Si.sub.3 N.sub.4 and/or Ge.sub.3 N.sub.4. The second dielectric layer may comprise a single layer of ZnS--SiO.sub.2, SiO.sub.2 or oxide of a rare earth metal. The second dielectric layer may also comprise a laminate of a dielectric layer 2a comprising ZnS--SiO.sub.2 on the side of the substrate and a dielectric layer 2b comprising SiO.sub.2 or oxide of a rare earth metal on the side of the reflective layer. The dielectric layer 1b has a thickness of 0.5 to 40 nm, and ratio of thickness of the dielectric layer 1b to the thickness of the first dielectric layer is up to 0.5.

Optical recording medium and its recording method

A method for preparing an optical recording medium of phase change type is provided. This recording medium comprises a substrate, a recording layer, and a lower and an upper dielectric layers provided in direct contact with the recording layer. In this method, a step of an exposure treatment wherein the surface of the lower dielectric layer is exposed to an oxidative atmosphere is conducted after forming the lower dielectric layer on the substrate and before forming the recording layer on the lower dielectric layer. A step of a heat treatment wherein said lower dielectric layer is heat treated may be carried out in addition to the exposure treatment.

Method for making an optical recording medium

The invention provides a phase charge type optical recording medium comprising on both sides of a recording layer dielectric layers, each containing zinc sulfide and silicon oxide as main components. The medium comprises on a substrate 2 a first dielectric layer 31, a recording layer 4, a second dielectric layer 32 and a reflective layer 5 made up of a metal. The first dielectric layer 32 comprises a dielectric lamina 1a on a substrate 2 side thereof and a dielectric lamina 1b on a recording layer 4 side thereof. The dielectric lamina 1a has a silicon oxide content of 2 to less than 40 mol %, the dielectric lamina 1b has a silicon oxide content of 40 to 100 mol %, and the second dielectric layer 32 has a silicon oxide content of 2 to 50 mol % and a thickness of 10 to 35 nm. The number of overwritable cycles can be increased.

Optical recording medium and read/write method therefor

An optical recording medium of phase change type with an increased number of overwritable operations and method for preparing such an optical recording medium is provided. In the optical recording medium of phase change type whose rate determining stage in the production has been the initialization of the recording layer, the time required for the production is reduced, and stable recording/reproducing properties are realized from the first overwriting operation. The optical recording medium comprises a transparent substrate and a recording layer on the transparent substrate. In the medium, the recording layer comprises at least one Sb-based thin film and at least one reactive thin film; the Sb-based thin film is in contact with said reactive thin film; the Sb-based thin film has been formed from an Sb-based material containing at least 95 at % of Sb; and the reactive thin film has been formed from an In-Ag-Te-based material mainly comprising In, Ag and Te or In, Ag, Te and Sb; and the reactive thin film contains 0.5 to 10 at % of oxygen. In the formation of the reactive thin film, the sputtering is conducted by introducing an inert gas and oxygen gas into the sputtering chamber.

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Nagano, Japan

Masanori Kosuda