Abstract: The present invention provides a test dummy wafer used in the process for manufacturing a semiconductor device, which has more excellent etching resistance than a silicon wafer, and excellent mirror surface properties and evenness required for a substrate, and which causes no contamination source in the manufacturing process. The dummy wafer is composed of glassy carbon, and at least one side thereof is preferably polished to a mirror surface having a surface roughness Ra of not more than 0.005 .mu.m. The dummy wafer of the present invention has excellent characteristics as a dummy wafer for monitoring the thickness of a CVD film. The dummy wafer having specific electric resistance of not more than 0.1 .OMEGA..multidot.cm exhibits excellent characteristics as a dummy wafer for monitoring the thickness of a film formed by sputtering and confirming cleanliness.

Abstract: A method for regenerating a used wafer or substrate by removing a functional coating film formed on the used wafer or substrate, comprising the steps of:(a) a step for sorting the used wafer or substrate according to the quality, structure or thickness of the functional coating film;(b) a step for removing the functional coating film, while in a state of holding the used wafer or substrate, (i) by lapping the objective face of the used wafer or substrate with a hard metal-bonded whetstone while applying an electrochemical in-process dressing, (ii) by polishing the objective face while dropping a fine-particle polishing slurry between a polishing plate provided with a pad and the functional coating film, or (iii) by electrolyzing the functional coating film on the objective face placed opposite to an electrode face in an electrolyte solution at a predetermined voltage;(c) a step for mechanically removing the functional coating film adhered to the end face at an adequate stage; and(d) a step for washing and dry

Abstract: A stator assembly of a rotary electric device is manufactured and assembled at reduced cost with an enhanced level of precision. A stator assembly of a rotary electric device comprising a yoke provided with a plurality of stationary magnetic poles and a yoke plate bonded to said yoke by means of synthetic resin in a mold to form an integral unit for enclosing a stator coil is assembled by bringing an alignment pin arranged on a jig for combining the yoke and the yoke plate into engagement with a corresponding alignment sections of the yoke and the yoke plate to put the yoke and the yoke plate together in order to produce a unitary stator assembly and a step of placing the unitary stator assembly of the yoke and the yoke plate in an injection metal mold with said alignment section fitted to an alignment pin arranged in the mold for mutual engagement and injecting synthetic resin into the mold to bond the yoke and the yoke plate together.

Abstract: A texture treatment for a carbon substrate of a magnetic disk or for a carbon overcoat layer of a magnetic disk is effective to prevent the generation of a stiction phenomenon between a magnetic head and the surface of a magnetic disk. The texture treatment for a carbon substrate or carbon overcoat of a magnetic disk involves the steps of: preparing the carbon disk surface; forming a catalytic material layer on the surface; and performing a heat treatment of the disks in an oxidizing atmosphere. Preferably, islands of catalytic material are formed on the surface by sputtering, and a laser heat treatment is used in an oxidizing atmosphere.

Abstract: A carbon substrate manufacturing method includes a hot molding step, a burn-carbonizing step, a hot isostatical pressure treatment step, and a mirror polishing step. In the hot molding step, molding is performed while heating thermosetting resin powders to be a hard carbon substrate after burn-carbonizing, where the thermosetting resin powders are of a particle size 150 .mu.m or more, HPF 80-150 mm, a moisture content 1.0-3.0 weight %, Fe, Ni, Si and Ca respectively 5 ppm or less. In the burn-carbonizing process, a disk shaped resin molded body is filled into a graphite cylinder and burn-carbonized by heating from the external while the condition therefor is maintained in that the disk shaped resin molded body is stacked holding therein a graphite spacer at every one sheet basis or at every plurality of sheet basis and is loaded on its top with a tungsten carbide weight, where the graphite spacer has a heat conductivity 100 kcal/m.hr..degree. C. or less, a bulk density 1.70-1.85, and a flatness degree 10 .mu.

Abstract: The surface of a blank for a textured amorphous carbon substrate is polished in a surface with a predetermined surface roughness, and then the blank with a polished surface is heated at a predetermined temperature in an oxidizing atmosphere to form minute irregularities in the polished surface through a reaction expressed by C+O.sub.2 =CO.sub.2 so that the surface is textured in an appropriate surface roughness. A randomly textured amorphous carbon substrate has a randomly textured surface with a surface roughness Ra in the range of 20 to 100 .ANG. and the ratio Ra.sub.2 /Ra.sub.1, where Ra.sub.1 is the surface roughness with respect to a circumferential direction, and Ra.sub.2 is the surface roughness with respect to a radial direction, in the range of 0.75 to 1.25 .ANG.. A concentrically textured amorphous carbon substrate has a concentrically textured surface with a surface roughness Ra in the range of 30 to 100 .ANG. or in the range of 40 to 200 .ANG., and the ratio Ra.sub.2 /Ra.sub.1 of 1.75 or greater.

Abstract: A method of manufacturing a magnetic recording medium such as for a magnetic disc, in which a magnetic layer comprising a Co-based alloy is formed on a carbon substrate and a heat treatment is applied at a temperature of 250.degree. to 1450.degree. C. to improve the coercive force. Further, the squareness ratio is improved by applying the heat treatment under a magnetic field. Greater coercive force can be obtained by forming a Cr underlayer prior to the formation of the magnetic layer. Increased recording density of the magnetic recording medium can be realized by improving the coercive force and the squareness ratio in this way.

Abstract: A carbon material is provided which comprises spherical crystal amorphous carbon having a void diameter in the crystallite of 30 .ANG. or below, and there is also provided a process of the production of a carbon material, in which a thermosetting resin that will be converted to amorphous carbon after using for the carbonization is molded, the molded thermosetting resin is preliminarily heated at a temperature of 1,000.degree. to 1,900.degree. C., and an isostatic pressure of 1,000 atmospheres or over is applied to the preliminarily heated body at a temperature of 2,050.degree. C. or over.