Abstract: The present invention provides a gallium nitride sintered body and a gallium nitride molded article which have high density and low oxygen content without using a special apparatus. According to the first embodiment, a gallium nitride sintered body, which is characterized by having density of 2.5 g/cm3 to less than 5.0 g/cm3 and an intensity ratio of the gallium oxide peak of the (002) plane to the gallium nitride peak of the (002) plane of less than 3%, which is determined by X-ray diffraction analysis, can be obtained. According to the second embodiment, a metal gallium-impregnated gallium nitride molded article, which is characterized by comprising a gallium nitride phase and a metal gallium phase that exist as separate phases and having a molar ratio, Ga/(Ga+N), of 55% to 80%, can be obtained.

Abstract: The present invention provides a gallium nitride sintered body and a gallium nitride molded article which have high density and low oxygen content without using a special apparatus. According to the first embodiment, a gallium nitride sintered body, which is characterized by having density of 2.5 g/cm3 to less than 5.0 g/cm3 and an intensity ratio of the gallium oxide peak of the (002) plane to the gallium nitride peak of the (002) plane of less than 3%, which is determined by X-ray diffraction analysis, can be obtained. According to the second embodiment, a metal gallium-impregnated gallium nitride molded article, which is characterized by comprising a gallium nitride phase and a metal gallium phase that exist as separate phases and having a molar ratio, Ga/(Ga+N), of 55% to 80%, can be obtained.

Abstract: The present invention provides a gallium nitride sintered body and a gallium nitride molded article which have high density and low oxygen content without using a special apparatus. According to the first embodiment, a gallium nitride sintered body, which is characterized by having density of 2.5 g/cm3 to less than 5.0 g/cm3 and an intensity ratio of the gallium oxide peak of the (002) plane to the gallium nitride peak of the (002) plane of less than 3%, which is determined by X-ray diffraction analysis, can be obtained. According to the second embodiment, a metal gallium-impregnated gallium nitride molded article, which is characterized by comprising a gallium nitride phase and a metal gallium phase that exist as separate phases and having a molar ratio, Ga/(Ga+N), of 55% to 80%, can be obtained.

Abstract: A subject for the invention is to provide a process for ceramic bead production in which ceramic beads with smooth surfaces are obtained by a simpler method without using a complicated process involving, for example, a DC plasma/radio-frequency plasma combination or a two-stage radio-frequency plasma. Another subject is to provide such ceramic beads. The invention relates to a technique in which a preheated raw ceramic material is introduced into a laminar-flow thermal plasma obtained using a high-voltage type direct-current (DC) plasma gun and is cooled and solidified and the resultant ceramic beads are collected.

Abstract: The present invention provides a gallium nitride sintered body and a gallium nitride molded article which have high density and low oxygen content without using a special apparatus. According to the first embodiment, a gallium nitride sintered body, which is characterized by having density of 2.5 g/cm3 to less than 5.0 g/cm3 and an intensity ratio of the gallium oxide peak of the (002) plane to the gallium nitride peak of the (002) plane of less than 3%, which is determined by X-ray diffraction analysis, can be obtained. According to the second embodiment, a metal gallium-impregnated gallium nitride molded article, which is characterized by comprising a gallium nitride phase and a metal gallium phase that exist as separate phases and having a molar ratio, Ga/(Ga+N), of 55% to 80%, can be obtained.

Abstract: A subject for the invention is to provide a process for ceramic bead production in which ceramic beads with smooth surfaces are obtained by a simpler method without using a complicated process involving, for example, a DC plasma/radio-frequency plasma combination or a two-stage radio-frequency plasma. Another subject is to provide such ceramic beads. The invention relates to a technique in which a preheated raw ceramic material is introduced into a laminar-flow thermal plasma obtained using a high-voltage type direct-current (DC) plasma gun and is cooled and solidified and the resultant ceramic beads are collected.

Abstract: A component for a vacuum apparatus for use in a plasma processing apparatus or a film forming apparatus for a semiconductor or the like, in which a surface is covered with a ceramic and/or metallic thermal spray film and projection-shaped particles of a width of 10-300 ?m, a height of 4-600 ?m and an average height/width ratio of 0.4 or higher are present within a range of 20-20,000 particle/mm2 on the surface of the thermal spray film. The thermal spray film has a porosity of 10-40%, shows a high adhering property to a film-shaped substance, is free from a product contamination by particles generated by a peeling of the film-shaped substance and can be continuously used over a prolonged period.

Abstract: A corrosion-resistant member comprising a base material having formed thereon a spayed coating having high corrosion resistance to corrosive gases or plasma, and a process of producing the same are disclosed. The corrosion-resistant member comprises a base material having formed thereon a sprayed coating, the sprayed coating being formed on the site of the base material to be exposed to corrosive gases or plasma and comprising Si, O, N, Group 2a element, and at least one element selected from the group consisting of Al, B, Zr and Ti, or comprises a base material having formed thereon a sprayed coating, the sprayed coating being formed on the site of the base material to be exposed to corrosive gases or plasma and comprising Si, O, N, Group 3a element, and at least one element selected from the group consisting of B, Zr and Ti.

Abstract: A corrosion-resistant member comprising a base material having formed thereon a spayed coating having high corrosion resistance to corrosive gases or plasma, and a process of producing the same are disclosed. The corrosion-resistant member comprises a base material having formed thereon a sprayed coating, the sprayed coating being formed on the site of the base material to be exposed to corrosive gases or plasma and comprising Si, O, N, Group 2a element, and at least one element selected from the group consisting of Al, B, Zr and Ti, or comprises a base material having formed thereon a sprayed coating, the sprayed coating being formed on the site of the base material to be exposed to corrosive gases or plasma and comprising Si, O, N, Group 3a element, and at least one element selected from the group consisting of B, Zr and Ti.

Abstract: In film-forming devices and plasma-processing devices, filmy matter adheres to the surfaces of the inner parts and it peels to cause dust and particles in the devices. In the devices, the dust and particles contaminate the objects for film formation thereon or the objects to be processed with plasma. For preventing the objects from being contaminated with them, the inner parts of the devices must be frequently exchanged every time when they have received any minor filmy matter thereon, and this lowers the productivity in the devices. When a modified glass part of which the surface is modified with spherical or bell-like island projections having a width and a height of from a few ?m to a few hundreds ?m is used in a film-forming device and in a plasma-processing device, then its ability to hold the filmy substance having adhered thereto is good and its resistance to plasma is also good.

Abstract: Parts, especially those formed of quartz glass, for film-forming devices, plasma-treating devices and the like have a problem of inner pollution of the devices with particles given by dropping of deposit films from the parts, a problem of hermetical sealing reduction due to bonding failure of the parts to other parts, and a problem of energy efficiency reduction due to the heat insulation failure in the parts. Parts having a thermal sprayed quartz glass film formed on a substrate have an increased ability to hold a deposit thereon, and have an increased ability to hermetically bond to other parts. The parts having a thermal sprayed black quartz glass film have an increased ability of heat insulation property. Even when washed with acid, the abilities of the parts do not lower. The parts can be used for a long period of time and their life is long.

Abstract: Members to be used in CVD devices, plasma treatment devices, etc. are exhausted by reaction with a corrosive gas or etching with plasma, and therefore, there were encountered problems such as staining of products due to the generation of particles and a reduction of the yield productivity. Also, glasses resistant to corrosive gases or plasma are weak in the heat resistance, and therefore, applications to be employed were limited. Members containing a heat-resisting base material having coated thereon a corrosion resistant glass containing at least one element selected from the group consisting of elements of the group 2a, group 3a and group 4a, especially an aluminosilicate or zirconia silicate based glass sprayed coating have high corrosion resistance to corrosive gases and plasma and high heat resistance and are less in the generation of particles.

Abstract: A corrosion-resistant member comprising a base material having formed thereon a spayed coating having high corrosion resistance to corrosive gases or plasma, and a process of producing the same are disclosed. The corrosion-resistant member comprises a base material having formed thereon a sprayed coating, the sprayed coating being formed on the site of the base material to be exposed to corrosive gases or plasma and comprising Si, O, N, Group 2a element, and at least one element selected from the group consisting of Al, B, Zr and Ti, or comprises a base material having formed thereon a sprayed coating, the sprayed coating being formed on the site of the base material to be exposed to corrosive gases or plasma and comprising Si, O, N, Group 3a element, and at least one element selected from the group consisting of B, Zr and Ti.

Abstract: In quartz glass parts and ceramic parts that are used in film-deposition devices and pre-cleaning devices in the production of semiconductors, etc., there are problems such as peeling off of the parts themselves during the use, peeling off of film-like substances adhered to the part surfaces, contamination of the products and short life time of the parts caused by corrosion of the part surfaces by plasma, and reduction in the productivity by frequent exchange of the parts. In quartz glass parts and ceramic parts that are used in film-deposition devices and pre-cleaning devices in the production of semiconductors, etc.

Abstract: A component for a vacuum apparatus for use in a plasma processing apparatus or a film forming apparatus for a semiconductor or the like, in which a surface is covered with a ceramic and/or metallic thermal spray film and projection-shaped particles of a width of 10-300 ?m, a height of 4-600 ?m and an average height/width ratio of 0.4 or higher are present within a range of 20-20,000 particle/mm2 on the surface of the thermal spray film. The thermal spray film has a porosity of 10-40%, shows a high adhering property to a film-shaped substance, is free from a product contamination by particles generated by a peeling of the film-shaped substance and can be continuously used over a prolonged period.

Abstract: Disclosed are magneto-optical recording media comprising at least a reflection layer, a recording layer and a dielectric layer laminated on a substrate in this order, wherein the thickness of the dielectric layer is not less than 140 nm or wherein the dielectric layer is provided by the lamination of upper dielectric layer and lower dielectric layer in which the thermal conductivity of the upper dielectric layer is higher than that of the lower dielectric layer. By arranging the thickness of the dielectric layer in a specific range, the surface roughness of a media in not more than 1.5 nm, and providing a reflection layer composed of a noble metal alloy, achieved is a magneto-optical recording medium able to record constantly in near-field magneto-optical recording, suitable for narrow track pitch, and having excellent SNR, resolution, and recording sensitivity.

Abstract: A near field optical recording medium having a header area in which at least an addressing signal or a timing signal is recorded by means of a concave/convex pattern with laser light using a flying optical head. When a concave/convex portion of the concave/convex pattern is to be detected, either an effect due to a change in returning light caused by distance wherein the reflectance is changed or an effect due to a change in returning light caused by a diffraction effect is sufficiently larger, or a combination of such effects (changes by distance effect and changes by diffraction effect) are not weakened by each other, so that header information recorded by the concave/convex pattern can correctly be reproduced even in a super-high density recording medium using near field light.

Abstract: Disclosed are magneto-optical recording media including at least a reflection layer, a recording layer and a dielectric layer laminated on a substrate in this order, wherein the thickness of the dielectric layer is not less than 140 nm or wherein the dielectric layer is provided by the lamination of upper dielectric layer and lower dielectric layer in which the thermal conductivity of the upper dielectric layer is higher than that of the lower dielectric layer. By arranging the thickness of the dielectric layer in a specific range, the surface roughness of a media in not more than 1.5 nm, and providing a reflection layer composed of a noble metal alloy, achieved is a magneto-optical recording medium able to record constantly in near-field magneto-optical recording, suitable for narrow track pitch, and having excellent SNR, resolution, and recording sensitivity.

Abstract: An optical recording medium able to reproduce address information during seeking in which an optical head moves between tracks, to increase seek speed, to improve recording/reproduction speed and to obtain a good header reproducing signal is achieved by that the concave portions or convex portions constituting a reproducing signal in seeking reproduced even during seek and/or constituting a timing signal for writing a header signal are connected to each other in a direction orthogonal to the tracks, when these concave portions and/or convex portions are placed in positions equivalent to each other in the adjacent tracks.

Abstract: In film-forming devices and plasma-processing devices, filmy matter adheres to the surfaces of the inner parts and it peels to cause dust and particles in the devices. In the devices, the dust and particles contaminate the objects for film formation thereon or the objects to be processed with plasma. For preventing the objects from being contaminated with them, the inner parts of the devices must be frequently exchanged every time when they have received any minor filmy matter thereon, and this lowers the productivity in the devices. When a modified glass part of which the surface is modified with spherical or bell-like island projections having a width and a height of from a few &mgr;m to a few hundreds &mgr;m is used in a film-forming device and in a plasma-processing device, then its ability to hold the filmy substance having adhered thereto is good and its resistance to plasma is also good.