Abstract: For a light emitting device using gallium nitride (GaN), on a substrate are sequentially formed a GaN-based layer, an AlGaN-based layer, and a light emitting layer. To prevent cracks in the AGaN-based layer, the AlGaN-based layer is formed before planarization of the surface of the GaN layer on a surface of the GaN layer which is not planar. For a laser, the AlGaN-based layers serve as clad layers which sandwich the light emitting layer.

Abstract: A GaN-based compound semiconductor device formed by sequentially forming, on a substrate, a GaN-based buffer layer and a GaN-based compound semiconductor layer. AlxGa1-xN1-yPy or AlxGa1-xN1-yAsy (0?x?1, 0<y<1) is used as the GaN-based buffer layer. N in AlxGa1-xN is partially substituted by P or As, whereby a buffer layer is grown at a high temperature. Thus, a difference in processing temperature between the process for growing a buffer layer and processes before and after the process is reduced. The GaN-based compound semiconductor layer formed on the buffer layer comprises a GaN-based layer, an n-type clad layer, a light-emitting layer, and a p-type clad layer. A multiple quantum well (MQW) layer formed from GaNP or GaNAs and GaN is inserted between the GaN-based layers, thereby reducing a dislocation density of the GaN-based layers.

Abstract: A method for manufacturing a nitride semiconductor device in which nitride crystals are sequentially grown on a substrate such as sapphire by MOCVD or the like, and p electrode and n electrode are formed. The wafer is not cut along two perpendicular directions, but rather is cut along two directions that form a 120 degree angle, to obtain a rhombus shaped semiconductor chip. Because the wafer has a six-fold rotation symmetry, by cutting the wafer at an angle of 120 degrees, the cutting directions are equivalent and the wafer can be cut in directions along which it can be easily split.

Abstract: A light-emitting device operating on a high drive voltage and a small drive current. LEDs (1) are two-dimensionally formed on an insulating substrate (10) of e.g., sapphire monolithically and connected in series to form an LED array. Two such LED arrays are connected to electrodes (32) in inverse parallel. Air-bridge wiring (28) is formed between the LEDs (1) and between the LEDs (1) and electrodes (32). The LED arrays are arranged zigzag to form a plurality of LEDs (1) to produce a high drive voltage and a small drive current. Two LED arrays are connected in inverse parallel, and therefore an AC power supply can be used as the power supply.

Abstract: An LED emitting light of wavelength mainly 375 nm or below. The LED includes a GaN layer (16), an n-clad layer (20), an AlInGaN buffer layer (22), a light emitting layer (24), a p-clad layer (26), a p-electrode (30), and an n-electrode (32) arranged on a substrate (10). The light emitting layer (24) has a multi-layer quantum well structure (MQW) in which an InGaN well layer and an AlInGaN barrier layer are superimposed. The quantum well structure increases the effective band gap of the InGaN well layer and reduces the light emitting wavelength. Moreover, by using the AlInGaN buffer layer (22) as the underlying layer of the light emitting layer (24), it is possible to effectively inject electrons into the light emitting layer (24), thereby increasing the light emitting efficiency.

Abstract: In order to provide a method for easily roughening a surface of a semiconductor constituting an LED, a first material 18 and a second material 20 having a property that they are nonuniformly mixed when thermally treated are deposited on a semiconductor 16, the structure is thermally treated, and etching is performed through reactive ion etching in which the etching rate with respect to the first material 18 is slower than the etching rates with respect to the second material 20 and to the semiconductor 16. During this process, a region 22 in which the first material 18 is the primary constituent functions as an etching mask, and a predetermined roughness can be easily formed on the surface of the semiconductor 16.

Abstract: A method for manufacturing a GaN compound semiconductor which can improve light emitting efficiency even when dislocations are present. An n type AlGaN layer, a undoped AlGaN layer, and a p type AlGaN layer are laminated on a substrate to obtain a double hetero structure. When the undoped AlGaN layer is formed, droplets of Ga or Al are formed on the n type AlGaN layer. The compositional ratio of Ga and Al in the undoped AlGaN layer varies due to the presence of the droplets, creating a spatial fluctuation in the band gap. Because of the spatial fluctuation in the band gap, the percentage of luminous recombinations of electrons and holes is increased.

Abstract: Yellow or oriental mustard seed can be fractionated to produce allyl isothiocyanate and p-hydroxybenzyl isothiocyanate, along with prepared mustard products, mustard protein and dietary fiber. Processes for the production of these various fractions from mustard seed stock are disclosed. The seed stock is comminuted with water to yield an activated slurry in which the enzyme myrosinase hydrolyses and deteriorates glycosinolates in the seed stock to isothiocyanates. Remaining slurry can then be sterilized and further conventionally processed to yield improved finished mustard products.

Abstract: The present invention provides a chemical vapor deposition apparatus for a semiconductor film, containing a horizontal tubular reactor, a susceptor, a heater, a feed gas introduction portion and a reaction gas exhaust portion, where part of the tubular reactor walls inclines downward from the upstream side of the feed gas passageway towards the downstream side thereof. The present invention also provides a chemical vapor deposition method using the apparatus.

Abstract: A GaN-based compound semiconductor device formed by sequentially forming, on a substrate, a GaN-based buffer layer and a GaN-based compound semiconductor layer. AlxGa1-xN1-yPy or AlxGa1-xN1-yAsy (0≦x≦1, 0<y<1) is used as the GaN-based buffer layer. N in AlxGa1-xN is partially substituted by P or As, whereby a buffer layer is grown at a high temperature. Thus, a difference in processing temperature between the process for growing a buffer layer and processes before and after the process is reduced. The GaN-based compound semiconductor layer formed on the buffer layer comprises a GaN-based layer, an n-type clad layer, a light-emitting layer, and a p-type clad layer. A multiple quantum well (MQW) layer formed from GaNP or GaNAs and GaN is inserted between the GaN-based layers, thereby reducing a dislocation density of the GaN-based layers.

Abstract: A gallium nitride-based light emitting element with improved light emission efficiency. A gallium nitride-based light emitting element is constructed by forming an n type GaN buffer layer, an n type GaN layer, an InGaN emissive layer, and a p type GaN layer in that order on a substrate, and forming a negative electrode and a positive electrode. A transparent ZnO electrode is formed on the p type GaN layer and abutting the positive electrode. Uniform current is supplied to the emissive layer by the ZnO electrode, and, at the same time, light from the emissive layer is transmitted through the ZnO electrode and externally emitted.

Abstract: In order to provide a method for easily roughening a surface of a semiconductor constituting an LED, a first material 18 and a second material 20 having a property that they are nonuniformly mixed when thermally treated are deposited on a semiconductor 16, the structure is thermally treated, and etching is performed through reactive ion etching in which the etching rate with respect to the first material 18 is slower than the etching rates with respect to the second material 20 and to the semiconductor 16. During this process, a region 22 in which the first material 18 is the primary constituent functions as an etching mask, and a predetermined roughness can be easily formed on the surface of the semiconductor 16.

Abstract: A method for manufacturing a GaN-based semiconductor device in which an ohmic contact can be provided between the semiconductor layer and the electrode material. In a method for manufacturing wherein an n-GaN layer, an emissive layer, a p-GaN layer are formed on a substrate in that order; etching is performed to expose a portion of the n-GaN layer; and a negative electrode is formed on the n-GaN layer, the etching is performed in two sub-steps, an etching step using BCl3 gas and an etching step using Cl2 gas. The surface of the n-GaN layer is exposed in the first sub-step and the B (boron) contamination layer is removed in the second sub-step.

Abstract: There are disclosed an apparatus and a method for chemical vapor deposition for a semiconductor film and the like, wherein a feed gas is supplied in a horizontal tubular reactor in the direction parallel to a substrate; a forcing gas is supplied therein in the direction perpendicular to the substrate; and the flow rate per unit area of the forcing gas which is supplied from a forcing gas introduction portion into the reactor is made lower in the central portion of the forcing gas introduction portion than in the peripheral portion thereof, or lower in the middle of a feed gas passageway than at both the end portions of the passageway.

Abstract: A method for manufacturing a GaN compound semiconductor which can improve light emitting efficiency even when dislocations are present. An n type AlGaN layer, a undoped AlGaN layer, and a p type AlGaN layer are laminated on a substrate to obtain a double hetero structure. When the undoped AlGaN layer is formed, droplets of Ga or Al are formed on the n type AlGaN layer. The compositional ratio of Ga and Al in the undoped AlGaN layer varies due to the presence of the droplets, creating a spatial fluctuation in the band gap. Because of the spatial fluctuation in the band gap, the percentage of luminous recombinations of electrons and holes is increased.

Abstract: A process is provided for the production of a pressed mustard cake from mustard seed, as well as mustard powder yielded from the milling of the mustard cake of the process. Employing strict temperature controls at key points in the process, this process yields a mustard cake and mustard powder of increased pungency, good flavor, enhanced protein content and enhanced preservability by limiting the degradation of key components in the mustard seed by excessive temperatures in the process.

Abstract: For a light emitting device using gallium nitride (GaN), on a substrate are sequentially formed a GaN-based layer, an AlGaN-based layer, and a light emitting layer. To prevent cracks in the AGaN-based layer, the AlGaN-based layer is formed before planarization of the surface of the GaN layer on a surface of the GaN layer which is not planar. For a laser, the AlGaN-based layers serve as clad layers which sandwich the light emitting layer.

Abstract: A light emitting element having a GaN layer and a light emitting layer formed on a substrate. A GaN layer is formed on a substrate so as to form a Ga-based light emitting layer. An AlGaN layer having a refractive index smaller than that of the light emitting layer or Al composition larger than that of the light emitting layer (18) is formed between the GaN layer (14) and the light emitting layer (18). Light from the light emitting layer (18) is reflected at the boundary relative to the AlGaN layer (16), so that light absorption in the GaN layer (14) is suppressed.

Abstract: There is disclosed a chemical vapor deposition apparatus of semi-conductor film comprising a horizontal type reaction tube equipped with a susceptor to carry a substrate, a heater to heat the substrate, an ingredient gas introduction zone arranged in a way that feeding direction to the reaction tube of the ingredient gas becomes substantially parallel to the substrate, and a reaction gas exhaust division, and further having a pressurized gas introduction zone on the wall of the reaction tube facing the substrate, wherein the structure of at least one part of the pressurized gas introduction zone at an upstream side of an ingredient gas passageway is such that the pressurized gas supplied from said part of the pressurized gas introduction zone is fed in an oblique down or a horizontal direction oriented to a downstream side of the ingredient gas passageway. Also, disclosed herein a chemical vapor deposition method using the apparatus.

Abstract: A production method of a GaN-based compound semiconductor having excellent crystallinity and a GaN-based semiconductor device produced therefrom. A discrete SiN buffer body is formed on a substrate, and a GaN buffer layer is formed thereon at low temperatures and a GaN semiconductor layer is then formed at high temperatures. By forming the discrete SiN buffer body, the crystal growth, which is dependent on the substrate, of the low-temperature buffer layer is inhibited and monocrystallization is promoted to generate seed crystals used at the time of growing the GaN buffer layer. Further, by forming SiO2 discretely between the substrate and the SiN buffer body or by forming InGaN or a superlattice layer on the GaN semiconductor layer, distortion of the GaN semiconductor layer is reduced.