Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Nobuaki Yasuda

Norio Ozawa

Yoshikatsu Takeoka

Katsutarou Ichihara

Akio Hori

Yoshiaki Terashima

Sumio Ikegawa

Shuichi Komatsu

Shinji Arai

Katsutaro Ichihara

Yoshinori Fujimori

Michiko Okubo

Masaaki Morita

Naoyuki Inoue

Sumio Ashida

Yasuhisa Oana

Hideki Ohkawa

Senji Shimanuki

Tetsuo Sadamasa

Masao Mashita

Takenobu Ogawa

Masato Yamashita

Satoshi Ishibashi, Legal Representative

Tomoyuki Ishibshi, Deceased

Hideo Sugai

In a film forming vessel, a substrate destined to carry on the surface thereof a thin film to be formed and a magnetron sputtering source integrally composed of an electric field supply means and a main magnetic field supply means for forming magnetron plasma in the neighborhood of the target and concurrently serving as a target holder for retaining a target in place are disposed as opposed to each other. An electromagnet as an auxiliary magnetic field supply means for decreasing the spatially dispersed amount of magnetron plasma in the neighborhood of the surface of the substrate is also laid out in the film forming vessel. A thin film of compound, for example, is formed on the substrate, with the spatially dispersed amount of magnetron plasma in the neighborhood of the surface of the substrate decreased as described above. As a result, the thin film of excellent quality is formed with high repeatability on a large surface area.

Sputtering apparatus and sputtering method

A plasma discharge apparatus includes a chamber in which plasma discharge is produced; an antenna composed of a loop coil formed from an electric conductor which can be supplied with R.F. power so as to produce a high frequency electric field in the chamber; and an electric shield of a shield layer of non-magnetic electrically conductive material which toroidally surrounds the coil and which has openings. The shield layer is grounded and electrically connected to the antenna so as to be a return circuit. The electric shield can be formed from a strip electric conductor toroidally wound to provide a spiral gap opening between turns. The strip can further be toroidally wound over the spiral gap but separated from the underlying strip layer to form a double layer shield.

Plasma discharge generating antenna

An optical recording medium and methods of manufacturing the same are disclosed. The optical recording medium is provided with a transparent adhesive layer containing organic compounds such as hydrocarbon or the like that constitute resin materials, and metallic compounds whose thermal expansion coefficients are nearly equal to those of inorganic transparent materials that constitute a transparent protective layer, whereby peel-off phenomena to be caused by secular variation can be avoided.

Optical recording medium and method of manufacturing the same

In a reversible memory system, a pulsed laser beam generated from a laser unit is directed to a recording layer formed on a substrate 1. The recording layer essentially consists of a recording medium, for example, an iron-nickel alloy containing iron as a major component and 27 to 30 atomic % of nickel, which undergoes martensite transformation from a low-temperature phase to a high-temperature phase at a predetermined temperature Af and which undergoes a stress-induced transformation at a characteristic temperature Md. When a region of the recording layer is irradiated with the laser beam having a predetermined intensity, the region undergoes a stress-induced transformation so that the region is changed from the high temperature phase to the low temperature phase.

Reversible memory structure for optical reading and writing and which is

There is disclosed a bubble-mode data-rewritable optical disc, which has a transparent substrate and a recording layer, formed on the substrate, for storing data to be optically rewritable. The substrate is at least partially formed of an organic material, which releases a gas component when it is heated at a radiation region of a data recording light beam. The recording layer is deposited on the substrate by co-sputtering or co-vacuum evaporation. The recording layer is made of a specific amorphous material containing silicon and fine metal particles. When the gas component is released from the substrate, the recording layer is deformed to be locally peeled off out of the substrate by pressure of the gas component, thus forming a protuberance. In a data erasing mode, a data erasing light beam is radiated onto the recording layer, which is then deformed so as to cause the protuberance to disappear, and has a substantially flat surface, thereby erasing the stored information.

Reversible optical recording medium with an optothermally deformable

A radiation-sensitive carrier body directly utilized as a stamper has a glass substrate, a first highly adhesive layer securely adhered to the substrate, a radiation-sensitive layer which discharges a gas component upon being irradiated with a laser beam and which locally forms a protuberance due to the absorbed energy, a second highly adhesive layer securely adhered to the specific material of the radiation-sensitive layer and which deforms in accordance with deformation of the layer, and a metal layer which has a high releasability to allow easy separation from a optical disk substrate material such as an acrylic material when the carrier body is used as a stamper substrate for manufacturing optical disks. A protuberance formed on the carrier body such as a continuous spiral protuberance allows formation of a corresponding spiral groove in the acrylic material, serving as a pre-track into which desired information will be digitally written by a user.

Radiation sensitive carrier body utilized as stamper structure

A rewritable information recording medium which has a recording layer containing a Group I transition element and a Group IV representative elements of the Periodic Table as two principal element and a support substrate for physically supporting the recording layer, and an information-write, -read, and erase method using this recording medium. When the recording layer is immediately cooled after it is heated up to near a eutectic temperature of the two principal elements, two metastable phases having different energy levels appear. A state in the first metastable phase of the higher energy level has a reflectivity sufficiently higher than that of a state of a mixed phase including the second metastable phase of the lower energy level, or that of the equilibrium state. The state in the first metastable phase can be obtained by heating a recording layer in another state by light beam irradiation. A portion in the first metastable state is cooled after it is heated to a temperature lower than that for obtaining the first metastable phase, so that it can be converted to a state of the low reflectivity, i.e., a state of a mixed phase including the second metastable phase or to the equilibrium state.

Information recording medium rewritable by utilizing two metastable

According to a disk-shaped magneto-optical recording medium of the invention, a transparent thin film serving as an interference layer is formed on a transparent substrate. The thin film is subjected to a plasma surface treatment, thereby decreasing the fused oxygen content in at least a surface portion thereof. A recording layer of a rare-earth-transition metal amorphous ferrimagnetic alloy thin film is formed on the plasma surface-treated film. Since the content of active, fused oxygen contained in at least the surface portion of the film decreases, rare-earth element oxide can hardly be formed in a boundary region between the recording layer and the transparent thin film. The content of the rare-earth element in this region is smaller than the average content in the overall recording layer.

Magneto-optical recording medium and manufacturing thereof

A magneto-optical recording disk has a transparent resinous substrate with a pre-groove, and a metallic recording layer formed above the substrate. A transparent adhesive layer is provided between the substrate and the recording layer, for allowing a laser beam to pass therethrough, and for causing the recording layer to be tightly adhered to the substrate to thereby prevent the recording layer from being peeled off from the substrate. The adhesive layer is comprised of a fluorine resin material.

Optical recording medium with fluorine resin adhesive

There is disclosed a method for manufacturing a bubble-mode optical disk having a recording layer made of a mixture of an indium oxide matrix containing indium clusters and organic clusters. The indium clusters absorb an energy of incident laser beam to heat the organic clusters which then release a gas component such that the matrix is locally deformed to form a protuberance. A plasma sputtering is used to deposit the recording layer on a disk substrate placed in a sputtering chamber. A target body used is made of indium. A low-pressure gaseous atmosphere in the chamber includes a methane series hydrocarbon gas and an oxygen gas. The gaseous atmosphere may include a hydrogen gas or a nitrogen gas.

Method for manufacturing bubble-mode optical recording media

A disk-shaped recording medium of the invention has a photosensitive recording layer formed on a substrate. Tellurium oxide clusters are dispersed in a hydrocarbon matrix of the recording layer so as to thermally stabilize the matrix. Tellurium clusters are dispersed in the matrix which is thermally stabilized by dispersion of the tellurium oxide clusters. The recording layer has excellent oxidation and heat resistance. The recording medium is manufactured by a plasma sputtering technique.

Information recording medium and manufacturing method thereof

In an optical disk, a single recording layer is formed on a transparent substrate. The recording layer has an insulative base layer in which metal clusters and organic clusters are uniformly contained. When radiation is incident on the recording layer such that the intensity of the radiation is changed in accordance with the type of recording information, the metal clusters absorb radiation energy. The organic clusters produce a gas component in accordance with a level of the radiation energy absorbed by the metal clusters, thereby causing the base layer to incur a local projection by a pressure of the gas component such that a protuberance is formed on the base layer.

Optical type information recording medium and manufacturing method

A data recording medium comprising, as a recording layer, a thin magnetic alloy film having an axis of easy magnetization along a direction perpendicular to the surface thereof, and an anticorrosion protective layer formed on the recording layer. This recording medium is featured in that the anticorrosion protective layer is formed of a thin oxide film which is obtained by subjecting the surface portion of the recording layer to an anodic oxidization. This protective layer may be further covered with a dielectric film as a second protective covering.

Data recording medium

An optical information recording medium is produced by introducing a plasma-generation gas comprising hydrocarbon into a plasma-generating region provided with a metal target and a substrate. The pressure of the plasma-generating gas is maintained within a predetermined range within the plasma-generating region. Electrical power is applied to the plasma-generating gas to dissociate the gas thereby forming a plasma. The generated plasma sputters the metal target, thereby allowing the sputtered metal to be deposited on the substrate in the form of a film containing the metal and the carbon liberated from the hydrocarbon. During sputtering, the product between the density of the power applied to the electrode and the average residence time of the plasma-generating gas within the plasma-generating region is controlled within such that the product falls within the range of more than 0.5 W-sec/cm.sup.2 and less than 50 W-sec/cm.sup.2, and the partial pressure of a secondary hydrocarbon, which is different from the introduced hydrocarbon, present during the dissociation to the secondary hydrocarbon before the dissociation and after the introduction is set to range between 2 and 12.

Method of producing an optical information recording medium

A disk-shaped optical type recording medium is disclosed which includes a transparent substrate and recording layer formed on the substrate. The recording layer in a single layer, which is made of a material capable of absorbing energy reaching it through the substrate and being locally raised on one surface according to the absorbed heat energy of the laser beam.

Growing community of inventors

Zushi, Japan

Nobuaki Yasuda