Abstract: A separator layer of Ti is formed on an auxiliary substrate of sapphire or the like. An undercoat layer of TiN is formed on the separator layer. The undercoat layer is provided so that a Group III nitride compound semiconductor layer can be grown with good crystallinity on the undercoat layer. TiN is sprayed on the undercoat layer to form a thermal spray depositing layer. Then, the separator layer is chemically etched to reveal the undercoat layer. Then, a Group III nitride compound semiconductor layer is grown on a surface of the undercoat layer.

Abstract: A first group III nitride compound layer, which is formed on a substrate by a method not using metal organic compounds as raw materials, is heated in an atmosphere of a mixture gas containing a hydrogen or nitrogen gas and an ammonia gas, so that the crystallinity of a second group III nitride compound semiconductor layer formed on the first group III nitride compound layer is improved. When the first group III nitride compound layer is formed on a substrate by a sputtering method, the thickness of the first group III nitride compound layer is set to be in a range of from 50 Å to 3000 Å.

Abstract: A first group III nitride compound layer, which is formed on a substrate by a method not using metal organic compounds as raw materials, is heated in an atmosphere of a mixture gas containing a hydrogen or nitrogen gas and an ammonia gas, so that the crystallinity of a second group III nitride compound semiconductor layer formed on the first group III nitride compound layer is improved. When the first group III nitride compound layer is formed on a substrate by a sputtering method, the thickness of the first group III nitride compound layer is set to be in a range of from 50 Å to 3000 Å.

Abstract: In an LED, the area of contact between an ohmic electrode formed on a contact layer and the contact layer serves as an effective light-emitting area of a light-emitting layer. Therefore, while the area of contact between the ohmic electrode and the contact layer is kept small, a seat electrode is interposed so that the seat electrode is connected to a circuit wiring on a wiring board by a ball electrode being contact with the seat electrode at an area larger than the area. As a result, the size necessary for forming the ball electrode can be secured easily and the light-emitting area of the light-emitting layer in the LED can be reduced sufficiently. Accordingly, a capacitance component formed by clamping the light-emitting portion of the light-emitting layer can be reduced, so that a time constant at a leading edge of luminance and a time constant at a trailing edge of luminance can be reduced sufficiently to obtain a high speed.

Abstract: The invention is to realize such a semiconductor light-emitting element which is higher in external quantum efficiency than an existing LED, and lower in production cost than an existing semiconductor laser. The light transmission insulating film is formed on a continuously incline face comprising the semiconductor layers having an opening angle etched in right angled V. The V shape inclined is formed by a known technique, and both left and right inclined faces have the angle of 45°. Depending on the length of &dgr; or the position of the light reflecting portion, probability that the light in duration of resonance is reflected may be made optimum or preferable. According to this structure, it is no longer necessary to carry but processing treatments of high degree, high precision, or high cost such as, e.g.

Abstract: A Group III nitride compound semiconductor light-emitting element has a reflecting surface on a side opposite to a main light-emitting surface of the element viewed from a light-emitting layer. The reflecting surface is inclined to surfaces of growth of semiconductor layers. Light emitted from the light-emitting layer is reflected by the reflecting surface, so that the reflected light emerges from side surfaces of the light-emitting element to the outside without passing through the semiconductor layers (particularly, the light-emitting layer).

Abstract: A group III nitride compound semiconductor device has a substrate and an AlN single crystal layer formed on the substrate. The AlN single crystal layer has a thickness of from 0.5 to 3 &mgr;m and has a substantially flat surface. The half-value width of an X-ray rocking curve of the AlN single crystal layer is not longer than 50 sec. In another device, a group III nitride compound semiconductor layer having a thickness of from 0.01 to 3.2 &mgr;m is grown at a temperature of from 1000 to 1180° C. on a sapphire substrate having a surface nitride layer having a thickness of not larger than 300 Å.

Abstract: A method of manufacturing a group III nitride compound semiconductor device, includes providing a substrate, forming a group III nitride compound semiconductor layer having a device function, and forming an undercoat layer between the substrate and the group III nitride semiconductor layer, the undercoat layer having a surface of a peak and trough structure.

Abstract: A titanium layer and a titanium nitride layer are successively laminated on a substrate and a group III nitride compound semiconductor layer is further formed thereon. When the titanium layer is removed in the condition that a sufficient film thickness is given to the titanium nitride layer, a device having the titanium nitride layer as a substrate is obtained.

Abstract: A group III nitride compound semiconductor device has a substrate and an AlN single crystal layer formed on the substrate. The AlN single crystal layer has a thickness of from 0.5 to 3 &mgr;m and has a substantially flat surface. The half-value width of an X-ray rocking curve of the AlN single crystal layer is not longer than 50 sec. In another device, a group III nitride compound semiconductor layer having a thickness of from 0.01 to 3.2 &mgr;m is grown at a temperature of from 1000 to 1180° C. on a sapphire substrate having a surface nitride layer having a thickness of not larger than 300 Å.

Abstract: A preferred condition for forming a Group III nitride compound semiconductor layer on a substrate by a sputtering method is proposed. When a first Group III nitride compound semiconductor layer is formed on a substrate by a sputtering method, an initial voltage of a sputtering apparatus is selected to be not higher than 110% of a sputtering voltage.

Abstract: A group III nitride compound semiconductor device has a substrate, a group III nitride compound semiconductor layer having a device function, and an undercoat layer formed between the substrate and the group III nitride semiconductor layer. The undercoat layer has a surface which has a texture structure, or which is trapezoid shaped in section or which is pit shaped. In addition, a reflection layer made of nitride of at least one metal selected from the group consisting of titanium, zirconium, hafnium and tantalum may be formed on a surface of the undercoat layer. Also the surface of the reflection layer is formed as a texture structure, a trapezoid shape in section or a pit shape.

Abstract: A group III nitride compound semiconductor device has a substrate, a group III nitride compound semiconductor layer having a device function, and an undercoat layer formed between the substrate and the group III nitride semiconductor layer. The undercoat layer has a surface which has a texture structure, or which is trapezoid shaped in section or which is pit shaped. In addition, a reflection layer made of nitride of at least one metal selected from the group consisting of titanium, zirconium, hafnium and tantalum may be formed on a surface of the undercoat layer. Also the surface of the reflection layer is formed as a texture structure, a trapezoid shape in section or a pit shape.

Abstract: An AlN layer having a surface of a texture structure is formed on a sapphire substrate. Then, a growth suppressing material layer is formed on the AlN layer so that the AlN layer is partially exposed to the outside. Then, group III nitride compound semiconductor layers are grown on the AlN layer and on the growth suppressing material layer by execution of an epitaxial lateral overgrowth method. Thus, a group III nitride compound semiconductor device is produced. An undercoat layer having convex portions each shaped like a truncated hexagonal pyramid is formed on a substrate. Group III nitride compound semiconductor layers having a device function are laminated successively on the undercoat layer.

Abstract: A group III nitride compound semiconductor device has a substrate, a group III nitride compound semiconductor layer having a device function, and an undercoat layer formed between the substrate and the group III nitride semiconductor layer. The undercoat layer has a surface which has a texture structure, or which is trapezoid shaped in section or which is pit shaped. In addition, a reflection layer made of nitride of at least one metal selected from the group consisting of titanium, zirconium, hafnium and tantalum may be formed on a surface of the undercoat layer. Also the surface of the reflection layer is formed as a texture structure, a trapezoid shape in section or a pit shape.

Abstract: A master brake cylinder comprises a reservoir and a cylinder for generating fluid pressure. Provided in the cylinder is a sliding piston, and mounted to front and rear ends of piston are piston cups for sealing a gap between the piston and the cylinder. The piston cups comprise a substrate made of rubber and a coating layer made of diamond-like carbon and provided on an outer peripheral surface (sliding surface) of the substrate. A surface of the coating layer constitutes a sliding surface, and so a frictional resistance thereof relative to an inner peripheral surface of the cylinder, on which the coating layer slides, is made relatively low. The coating layer can easily follow deformation of the substrate and securely adheres to the substrate.

Abstract: A method for manufacturing a resin product with a mold having at least two molds opposed to each other. Each of the molds 5 has a cavity surface defining a space therebetween. The method includes the steps of performing an ionic nitriding treatment to at least a part of at least one cavity surface to form fine projections and recesses therein. A nitride layer is provided on the one cavity surface. The method further includes filling the space with a plastic resin material, solidifying the resin material, and removing the solidified resin material from the mold.

Abstract: A sealing apparatus, which provides a seal between a metal surface and a member sliding along the metal surface is made of rubber material which contains a rubber polymer having alkyl lateral chains. At least a part of alkyl group hydrogen of rubber polymer in cortex is substituted from fluorine by plasma treatment. The plasma treatment reduces the noise which is normally present in device as of this type.

Abstract: Method and apparatus for improving the surface quality of a resin molding by treating it with a plasma gas, measuring and integrating ion density and stopping the treatment when the integration reaches a predetermined value.

Abstract: An electrochromic element comprising a pair of electrode films, at least one of which is a transparent electrode film, a color forming film laminated between both the electrode films and an electrolyte. The color forming film is formed on the electrode film by depositing thereon a conductive metal oxide such as indium oxide and tungsten oxide. The depositing ratio of tungsten oxide and indium oxide preferably is within the range of 10:1 to 3:1 by weight ratio.