Abstract: The present invention restricts defect density on the magnetic disk based on predetermined polishing conditions by applying a magnetic field to the entire surface of a magnetic disk in a direction vertical thereto, rotating the magnetic disk, loading a magnetic head to the magnetic disk, reproducing signals from the magnetic disk, processing the reproduced signals by a waveform analyzer, counting pulse waveforms of 0.9 times or more a servo-bit length at ½ threshold value of an average output, and measuring the defect density on the magnetic disk giving an undesired effect on the I/O performance of the magnetic disk drive. In a case of a magnetic recording medium using a vertical magnetic recording system, even with fine defect of magnetic layer, a servo pattern cannot be judged correctly. This provides degradation of the I/O performance of increasing the time necessary for reading out large capacity data, lowering the performance of the entire magnetic disk drive.

Abstract: Embodiments of the invention provide a magnetic disk capable of maintaining a satisfactory sliding resistance and having a high corrosion resistance and a manufacturing method thereof. The magnetic disk and the manufacturing method thereof are realized by forming a protection film having a less film thickness distribution on a magnetic film surface, particularly by reducing a film thickness distribution in a load/unload zone in addition to a reduction in film thickness of the protection film. In one embodiment, a shortest distance between a substrate and a supporting member is 10 mm or more in a step of forming the protection film, the substrate being mounted on a holder having claws for holding the substrate and supporting members for supporting the claws. In addition, the method is characterized by chamfering the face confronting the substrate of the supporting member and setting the shortest distance between the substrate and the supporting member to 5 mm or more.

Abstract: A thin film magnetic disc in which dot-like scattered bumps, made of a material different from that of the protective layer, are formed on the protective layer, and a lubricant layer is formed on the surfaces of the protective layer and the scattered bumps. A protective layer excellent in strength and disk durability is obtained by using a material different from that of the bumps. The functions of the protective layer and scattered bumps are separated from each other and make full use of the different materials. Such a protective layer is effective to reduce spacing between a head and the disc.

Abstract: A plasma processing apparatus comprising: a vacuum container; an evacuation means for keeping the interior of the vacuum container at a pressure not higher than atmospheric pressure; a substrate support device for supporting a substrate to be subjected to plasma processing; an electrode for generating plasma in cooperation with the substrate support; a voltage supply for applying a voltage to the electrode; a gas introducing system for introducing a gaseous material into a space where the plasma is produced; a surrounding member for enclosing the space above the substrate support, and a drive for relatively moving the surrounding member to space an end of the surrounding member proximate from the substrate from at least one of the substrate support and the substrate supported thereon by a distance which is short enough to suppress plasma leakage during the plasma processing and to position the end of the surrounding member away from said at least one of the substrate support and the substrate thereon for char

Abstract: Disclosed are a recording medium comprising a substrate, a thin film for recording formed on at least one side of the substrate, a protective layer formed on the thin film, and a lubricative film formed on the protective layer, the lubricative film comprising an oxidative polymerization product having main molecular chains chemically bonded to the protective film; and a process for producing the recording medium. This recording medium is excellent in lubricity and durability, and the layers formed thereon can be very thin.

Abstract: A surface treatment method and apparatus permitting the treatment of a film with plasma with a high treatment speed and a high efficiency without uselessly complicating the construction of a device for realizing it are disclosed. The area where the counter electrode is in contact with the plasma is sufficiently larger than the area where the rotating electrode is in contact therewith. The ratio of the areas is preferably not smaller than 1.5 and the etching speed may be increased to a value more than ten times as great as that obtained by a prior art method.

Abstract: A magnetic disk comprising a nonmagnetic substrate, a metallic thin film magnetic layer provided on the substrate and a hard carbon protective layer provided on the magnetic layer, the hard carbon protective layer containing at least one metal element of silicon, germanium, tin and lead, or further containing fluorine, formed by bias plasma CVD treatment, has a high attrition resistance, a high peeling resistance and a high crack resistance or further a higher corrosion resistance.

Abstract: The magnetic recording medium of the present invention comprises(a) a non-magnetic substrate,(b) a magnetic recording layer containing at least one ferromagnetic substance on at least one side of the substrate,(c) a protective layer the magnetic recording layer, and(d) a lubricant layer on the protective layer, wherein an adhesion-strengthening substance which is at least one member selected from the group consisting of metals and metal compounds is distributed substantially uniformly on the layer (c) at the interface between the layer (c) and the layer (d) so as not to cover the whole surface of the layer (c) and so as to contact also with the layer (d).

Abstract: An optical recording medium is made by sputtering a polymeric material in an evacuated chamber to form an under layer on a substrate having a preformed grooved pattern of prepits and pregrooves, and then forming a recording layer on the underlayer in the chamber continuously after forming the underlayer. Said under layer is made of a high polymeric material which can be melted, sublimated, or decomposed at a lower temperature than the melting point, the sublimating point, or the decomposing temperature of said recording layer. Accordingly, said under layer can relax the thermal shock transferred from said substrate into said recording layer, and the deformation of said substrate can be prevented, even though a laser beam for playback is repeatedly radiated onto said recording layer, and said optical recording medium has a larger recording sensitivity than the recording sensitivity of an optical recording disc of a prior art.

Abstract: In an optical recording medium, an under layer is formed between an even pattern of a substrate and a recording layer, and said under layer is made of a high polymeric material which can be melted, sublimated, or decomposed at a lower temperature than the melting point, the sublimating point, or the decomposing temperature of said recording layer. Accordingly, said under layer can relax the thermal shock transferred from said substrate into said recording layer, and the deformation of said substrate can be prevented, even through a laser beam for playback is repeatedly radiated onto said recording layer, and said optical recording medium has a larger recording sensitivity than the recording sensitivity of an optical recording disc of a prior art.