Abstract: A method for manufacturing a semiconductor device includes forming, on first and second impurity layers on a termination region side, an insulating layer, forming a first metal film and a second metal film in this order on the insulating layer and a drift layer, performing dry etching on the first and second metal films all together so that a position of a first end of a metallized layer, which is a remaining part of the first metal film, in the interface region on the termination region side and a position of a second end of an electrode, which is a remaining part of the second metal film, in the interface region on the terminal region side are the same in plan view. The first and second ends are closer to the active region than an end of the second impurity layer on the termination region side in plan view.

Abstract: A substrate for use as a disk substrate in a hard disk drive or the like, an information recording medium such as a magnetic disk, and a starting material glass plate which is a starting material of the substrate for information recording media. The forming conditions of the starting material glass plate are controlled such that the starting material glass plate has a long-wavelength waviness of not more than 6 nm. This starting material glass plate is polished so as to have a long-wavelength waviness of not more than 6 nm using CeO2 abrasive grains having a mean grain diameter of not less than 0.01 ?pm and a 90% diameter of the volume grain size distribution of not less than 0.02 ?m. The resulting substrate for an information recording medium has an excellent planarity, can be obtained in a short time and with a low polishing amount, and the resulting information recording medium is able to cope with increased data zone recording density.

Abstract: A substrate for use as a disk substrate in a hard disk drive or the like, an information recording medium such as a magnetic disk, and a starting material glass plate which is a starting material of the substrate for information recording media. The forming conditions of the starting material glass plate are controlled such that the starting material glass plate has a long-wavelength waviness of not more than 6 nm. This starting material glass plate is polished so as to have a long-wavelength waviness of not more than 6 nm using CeO2 abrasive grains having a mean grain diameter of not less than 0.01 ?m and a 90% diameter of the volume grain size distribution of not less than 0.02 ?m. The resulting substrate for an information recording medium has an excellent planarity, can be obtained in a short time and with a low polishing amount, and the resulting information recording medium is able to cope with increased data zone recording density.

Abstract: There are provided a substrate for information recording media and a manufacturing method thereof, according to which the projection height of minute undulations formed on the substrate surfaces can be made more uniform, and variation in the projection density can be suppressed. First, chemical strengthening treatment is carried out on a glass substrate that has been prepared by processing a sheet-shaped starting material glass plate into a predetermined shape. Then, precision polishing is carried out on the glass substrate that has been subjected to the chemical strengthening treatment, such that a polishing amount in a thickness direction of the glass substrate is within a predetermined range. Finally, surface washing is carried out on the glass substrate that has been subjected to said precision polishing.

Abstract: A glass substrate for a data recording medium is disk-shaped and has a circular bore at the center portion. At least one of an inner circumferential end surface and an outer circumferential end surface is smooth. The smooth surface is formed by exposing at least one of the inner circumferential end surface and the outer circumferential end surface of a glass disk to a laser beam. During laser machining, the end surface of the glass disk that is exposed to the laser beam is heated and melted. Therefore, minute cracks, formed on the end surface of the glass disk before the laser machining, are eliminated. As a result, the strength of the glass substrate is maintained without a chemical strengthening treatment. This eliminates disadvantages caused by the chemical strengthening step.

Abstract: The present invention provides a method which can simultaneously grind inner peripheral edges and outer peripheral edges of a multiplicity of glass substrates used for magnetic storage media or the like. In order to chamfer the outer edges of the glass substrates g, a multiplicity of annular glass substrates g are firstly stacked with buffer sheets 5 interposed between the glass substrates to make a glass substrate block G. Then, a first plates 1, 1 of the above described clamping jig are applied to both sides of the glass substrate block G, and a first fastening tool 3 is inserted through center holes of the first plates 1, 1 and the glass substrate block G. Next, the glass substrate block G is clamped from an inside thereof for chamfering the outer edges with a grindstone 6.

Abstract: There are provided a method of manufacturing a glass substrate for information recording media that allows the inner and outer peripheral edge surfaces of the glass substrate for information recording media to be smoothed easily and inexpensively, a glass substrate for information recording media manufactured using this method, and an information recording medium using this glass substrate. A donut-shaped glass disk for information recording media having an outer peripheral edge surface and an inner peripheral edge surface is prepared. At least one of the outer peripheral edge surface and the inner peripheral edge surface of the glass disk is smoothed by melt-heating to a temperature at or above the softening point of the glass by irradiating with at least one laser beam.

Abstract: There is provided a glass substrate for magnetic recording media, which enables damage to a magnetic recording medium using the glass substrate to be prevented. The glass substrate is a donut-shaped glass substrate comprising major surfaces, an outer peripheral edge surface, an inner peripheral edge surface, and chamfered surfaces, each connecting between one of the major surfaces and one of the outer peripheral edge surface and the inner peripheral edge surface. Each of the chamfered surfaces comprises a conical surface part and an annular curved surface part connected to one another, and for each of the chamfered surfaces, a percentage ratio of a length of an outline of the annular curved surface part to a length of an outline of the chamfered surface in a cross section of the glass substrate including a central axis of the glass substrate is not less than a predetermined value.

Abstract: There are provided a substrate for information recording media and a manufacturing method thereof, according to which the projection height of minute undulations formed on the substrate surfaces can be made more uniform, and variation in the projection density can be suppressed. First, chemical strengthening treatment is carried out on a glass substrate that has been prepared by processing a sheet-shaped starting material glass plate into a predetermined shape. Then, precision polishing is carried out on the glass substrate that has been subjected to the chemical strengthening treatment, such that a polishing amount in a thickness direction of the glass substrate is within a predetermined range. Finally, surface washing is carried out on the glass substrate that has been subjected to said precision polishing.

Abstract: A glass substrate for a data recording medium is disk-shaped and has a circular bore at the center portion. At least one of an inner circumferential end surface and an outer circumferential end surface is smooth. The smooth surface is formed by exposing at least one of the inner circumferential end surface and the outer circumferential end surface of a glass disk to a laser beam. During laser machining, the end surface of the glass disk that is exposed to the laser beam is heated and melted. Therefore, minute cracks, formed on the end surface of the glass disk before the laser machining, are eliminated. As a result, the strength of the glass substrate is maintained without a chemical strengthening treatment. This eliminates disadvantages caused by the chemical strengthening step.

Abstract: The present invention provides a method which can simultaneously grind inner peripheral edges and outer peripheral edges of a multiplicity of glass substrates used for magnetic storage media or the like.

Abstract: There is provided a glass substrate for magnetic recording media, which enables damage to a magnetic recording medium using the glass substrate to be prevented. The glass substrate is a donut-shaped glass substrate comprising major surfaces, an outer peripheral edge surface, an inner peripheral edge surface, and chamfered surfaces, each connecting between one of the major surfaces and one of the outer peripheral edge surface and the inner peripheral edge surface. Each of the chamfered surfaces comprises a conical surface part and an annular curved surface part connected to one another, and for each of the chamfered surfaces, a percentage ratio of a length of an outline of the annular curved surface part to a length of an outline of the chamfered surface in a cross section of the glass substrate including a central axis of the glass substrate is not less than a predetermined value.

Abstract: There are provided a method of manufacturing a glass substrate for information recording media that allows the inner and outer peripheral edge surfaces of the glass substrate for information recording media to be smoothed easily and inexpensively, a glass substrate for information recording media manufactured using this method, and an information recording medium using this glass substrate. A donut-shaped glass disk for information recording media having an outer peripheral edge surface and an inner peripheral edge surface is prepared. At least one of the outer peripheral edge surface and the inner peripheral edge surface of the glass disk is smoothed by melt-heating to a temperature at or above the softening point of the glass by irradiating with at least one laser beam.