Abstract: A GaN layer is grown on a sapphire substrate, an SiO2 film is formed on the GaN layer, and a GaN semiconductor layer including an MQW active layer is then grown on the GaN layer and the SiO2 film using epitaxial lateral overgrowth. The GaN based semiconductor layer is removed by etching except in a region on the SiO2 film, and a p electrode is then formed on the top surface of the GaN based semiconductor layer on the SiO2 film, to join the p electrode on the GaN based semiconductor layer to an ohmic electrode on a GaAs substrate. An n electrode is formed on the top surface of the GaN based semiconductor layer.

Abstract: In the manufacture of a semiconductor laser device, sequentially grown on a sapphire substrate in the following order are a buffer layer, a first undoped GaN layer, a first super lattice defect reducing layer, a second undoped GaN layer, a second super lattice defect reducing layer, a third undoped GaN layer, a third super lattice defect reducing layer and a fourth undoped GaN layer. A device structure is then formed thereon. The first to third super lattice defect reducing layers each include five pairs of InGaN and AlGaN films alternately placed on one another in this order.

Abstract: It is an object of the present invention to provide a simulation tool, which can overcome complications of examinations by simulations as described above and can provide a designer with easy examinations. A simulation based on a design parameter of a unit is implemented. Furthermore, a simulation result implemented by the control device is output on a display screen as a graph. Then, the unit design parameter is corrected in accordance with a correction in the graph displayed on the display screen. Thus, the simulation can be retried easily.

Abstract: An object of the present invention is to provide an untempered free-machining steel to be nitrided, not containing Pb, capable of securing a predetermined strength and hardness and having machinability higher than steel containing Pb; and nitrided products. To be more specific, the present invention relates to a bainite-type untempered free-machining steel to be nitrided containing C: 0.05 to 0.8 wt %, Si: 0.01 to 2.5 wt %, Mn: 0.1 to 3.5 wt %, P: 0.001 to 0.2 wt %, S: 0.01 to 0.2 wt %, Cr: 1.0 to 3.5 wt %, V: 0.1 to 0.5 wt %, Al: 0.001 to 0.020 wt %, Ca: 0.0005 to 0.02 wt %, and O: 0.0005 to 0.01 wt % and the residue with an alloy composition of unavoidable impurities and Fe as its basic alloy composition, provided that a content of each of the Mn, the S and the Cr satisfy the formula: ([Mn]?55×[S]/32+[Cr])>2.0, in which an occupation area of a sulfide inclusion present in contact with an oxide inclusion containing 8 to 62 wt % of CaO and containing not less than 1.0 wt % of Ca is not less than 2.

Abstract: An n-current blocking layer is formed by alternately stacking an n-first current blocking layer of a nitride based semiconductor containing Al or B and an n-second current blocking layer of a nitride based semiconductor containing In. In a semiconductor laser device having a real refractive index guided structure, the mean refractive index of the n-current block layer is smaller than the refractive indices of a p-first cladding layer and a p-second cladding layer. In a semiconductor laser device having a loss guided structure, the mean band gap of the n-current blocking layer is substantially equal to or smaller than the mean band gap of an active layer.

Abstract: In the manufacture of a semiconductor laser device, a low temperature buffer layer is grown on a sapphire substrate at a growth rate of 25 to 30 Å/sec. On the low temperature buffer layer, an n-GaN layer, a anti-crack layer, an n-cladding layer, an n-guide layer, an MQW active layer, a p-carrier blocking layer, a p-guide layer, a p-cladding layer and a p-contact layer are grown in this order. The growth of the low temperature buffer layer at the high growth rate allows a good low temperature buffer layer to be stably provided with good reproducibility. Thus, good crystallinity and electrical characteristics can stably be provided in the above layers.

Abstract: Disclosed is a free-cutting steel for machine structural use which always exhibits desired machinability, particularly, machinability by cutting with cemented carbide tools. This free-cutting steel is produced by preparing a molten alloy of the composition consisting essentially of, by weight %, C: 0.05-0.8%, Si: 0.01-2.5%, Mn: 0.1-3.5% and O: 0.0005-0.01%, the balance being Fe and inevitable, and adjusting the addition amounts of Al and Ca in such a manner as to satisfy the above ranges, S: 0.01-0.2%, Al: 0.001-0.020% and Ca: 0.0005-0.02%, and the conditions of [S]/[O]: 8-40 [Ca]×[S]: 1×10−5−1×10−3 [Ca]/[S]: 0.01-20 and [Al]: 0.001-0.020% to obtain a steel characterized in that the area in microscopic field occupied by the sulfide inclusions containing Ca of 1.0% or more neighboring to oxide inclusions containing CaO of 8-62% is 2.0×10−4 mm2 or more per 3.5 mm2.

Abstract: An aided design apparatus including data output means for outputting data of an attribute name associated with an attribute group of a part used for transporting a sheet along with three-dimensional shape data of the part.

Abstract: Disclosed is a steel for machine structural use having good machinability and chip-breakability as well as a method of producing the steel. The steel consists essentially of, by wt. %, C: 0.05-0.8%, Si: 0.01-2.0%, Mn: 0.1-3.5%, S: 0.01-0.2%, Al: 0.001-0.020%, Ca: 0.0005-0.02%, O: 0.0005-0.01% and N: 0.001-0.04%, and further, one or both of Ti: 0.002-0.010% and Zr: 0.002-0.025%, the balance being Fe and inevitable impurities. At production of the steel controlled deoxidization is conducted by operation meeting certain conditions so that at least a certain amount of “duplex inclusion” having a specific chemical composition may be formed, and Ti and/or Zr is added to precipitate finely dispersed MnS inclusion particles with nuclei of Ti-oxide and/or Zr-oxide. The finely dispersed MnS inclusions must share a determined part of the total sulfide inclusions.

Abstract: A thin nitride-based semiconductor layer having a low dislocation density is formed by laterally growing a nitride-based semiconductor layer on the upper surface of an underlayer and forming quantum dots on the laterally grown nitride-based semiconductor layer. The number of dislocations is reduced by a single lateral growth and is further reduced due to a dislocation loop effect by the quantum dots, without repeating lateral growth.

Abstract: A nitride-based semiconductor light-emitting device capable of improving luminous efficiency by reducing light absorption loss in a contact layer is provided. This nitride-based semiconductor light-emitting device comprises a first conductivity type first nitride-based semiconductor layer formed on a substrate, an active layer, formed on the first nitride-based semiconductor layer, consisting of a nitride-based semiconductor layer, a second conductivity type second nitride-based semiconductor layer formed on the active layer, an undoped contact layer formed on the second nitride-based semiconductor layer and an electrode formed on the undoped contact layer.

Abstract: A nitride-based semiconductor laser device capable of attaining stabilization of a laser beam and inhibiting a threshold current and an operating current from increase is provided. This nitride-based semiconductor laser device comprises a substrate consisting of either a nitride-based semiconductor doped with an impurity or a boride-based material, an n-type cladding layer formed on the substrate, an active layer consisting of a nitride-based semiconductor formed on the n-type cladding layer, a p-type cladding layer formed on the active layer and a light guide layer formed only between the active layer and the p-type cladding layer in the interspaces between the active layer and the n- and p-type cladding layers.

Abstract: A nitride-based semiconductor light-emitting device capable of attaining homogeneous emission with a low driving voltage is obtained. This nitride-based semiconductor light-emitting device comprises a first conductivity type first nitride-based semiconductor layer formed on a substrate, an emission layer, consisting of a nitride-based semiconductor, formed on the first nitride-based semiconductor layer, a second conductivity type second nitride-based semiconductor layer formed on the emission layer, a second conductivity type intermediate layer, consisting of a nitride-based semiconductor, formed on the second nitride-based semiconductor layer, a second conductivity type contact layer, including a nitride-based semiconductor layer having a smaller band gap than gallium nitride, formed on the intermediate layer, and a light-transmitting electrode formed on the contact layer.

Abstract: Disclosed is a steel for machine structural use having good machinability and chip-breakability as well as a method of producing the steel. The steel consists essentially of, by wt. %, C: 0.05-0.8%, Si: 0.01-2.0%, Mn: 0.1-3.5%, S: 0.01-0.2%, Al: 0.001-0.020%, Ca: 0.0005-0.02%, O: 0.0005-0.01% and N: 0.001-0.04%, and further, one or both of Ti: 0.002-0.010% and Zr: 0.002-0.025%, the balance being Fe and inevitable impurities. At production of the steel controlled deoxidization is conducted by operation meeting certain conditions so that at least a certain amount of “duplex inclusion” having a specific chemical composition may be formed, and Ti and/or Zr is added to precipitate finely dispersed MnS inclusion particles with nuclei of Ti-oxide and/or Zr-oxide. The finely dispersed MnS inclusions must share a determined part of the total sulfide inclusions.

Abstract: In the manufacture of a semiconductor laser device, sequentially grown on a sapphire substrate in the following order are a buffer layer, a first undoped GaN layer, a first super lattice defect reducing layer, a second undoped GaN layer, a second super lattice defect reducing layer, a third undoped GaN layer, a third super lattice defect reducing layer and a fourth undoped GaN layer. A device structure is then formed thereon. The first to third super lattice defect reducing layers each include five pairs of InGaN and AlGaN films alternately placed on one another in this order.

Abstract: A nitride-based semiconductor laser device capable of elongating the life thereof is obtained. This nitride-based semiconductor laser device comprises a first cladding layer consisting of a first conductivity type nitride-based semiconductor, an emission layer, formed on the first cladding layer, consisting of a nitride-based semiconductor and a second cladding layer, formed on the emission layer, consisting of a second conductivity type nitride-based semiconductor, while the emission layer includes an active layer emitting light, a light guiding layer for confining light and a carrier blocking layer, arranged between the active layer and the light guiding layer, having a larger band gap than the light guiding layer.

Abstract: Disclosed is a free-cutting steel for machine structural use which always exhibits desired machinability, particularly, machinability by cutting with cemented carbide tools. This free-cutting steel is produced by preparing a molten alloy of the composition consisting essentially of, by weight %, C: 0.05-0.8%, Si: 0.01-2.5%, Mn: 0.1-3.5% and O: 0.0005-0.01%, the balance being Fe and inevitable, and adjusting the addition amounts of Al and Ca in such a manner as to satisfy the above ranges, S: 0.01-0.2%, Al: 0.001-0.020% and Ca: 0.00050-0.02%, and the conditions of [S]/[O]: 8-40 [Ca]×[S]: 1×10−5−1×10−3 [Ca]/[S]: 0.01-20 and [Al]: 0001-0.020% to obtain a steel characterized in that the area in microscopic field occupied by the sulfide inclusions containing Ca of 1.0% or more neighboring to oxide inclusions containing CaO of 8-62% is 2.0×10−4 mm2 or more per 3.5 mm2.

Abstract: In the manufacture of a semiconductor laser device, sequentially grown on a sapphire substrate in the following order are a buffer layer, a first undoped GaN layer, a first super lattice defect reducing layer, a second undoped GaN layer, a second super lattice defect reducing layer, a third undoped GaN layer, a third super lattice defect reducing layer and a fourth undoped GaN layer. A device structure is then formed thereon. The first to third super lattice defect reducing layers each include five pairs of InGaN and AlGaN films alternately placed on one another in this order.

Abstract: A nitride-based semiconductor light-emitting device capable of attaining homogeneous emission with a low driving voltage is obtained. This nitride-based semiconductor light-emitting device comprises a first conductivity type first nitride-based semiconductor layer formed on a substrate, an emission layer, consisting of a nitride-based semiconductor, formed on the first nitride-based semiconductor layer, a second conductivity type second nitride-based semiconductor layer formed on the emission layer, a second conductivity type intermediate layer, consisting of a nitride-based semiconductor, formed on the second nitride-based semiconductor layer, a second conductivity type contact layer, including a nitride-based semiconductor layer having a smaller band gap than gallium nitride, formed on the intermediate layer, and a light-transmitting electrode formed on the contact layer.

Abstract: A method of forming a nitride-based semiconductor capable of forming a nitride-based semiconductor layer having low dislocation density with a small thickness is obtained. This method of forming a nitride-based semiconductor comprises steps of laterally growing a nitride-based semiconductor layer on the upper surface of an underlayer and forming quantum dots on the laterally grown nitride-based semiconductor layer. Thus, the number of dislocations reduced by lateral growth is further reduced due to a dislocation loop effect by the quantum dots. Therefore, a nitride-based semiconductor having lower dislocation density is formed as compared with a case of reducing the number of dislocations only by lateral growth.