Abstract: A light confinement layer constructed of a semiconductor that has a refractive index different from that of p-type second cladding layers is formed to a small film thickness of not greater than 2 ?m (about 0.5 ?m) on the whole surface of ridge portions of two semiconductor lasers. Thus, the light confinement layer on the ridge portions is made roughly flat so as to be easily removable by etching. As a result, the exposure of p-type second cladding layers of the ridge portions due to deep etching is prevented to allow the confinement of light into the p-type cladding layers to be stably effected. A dielectric film is formed on the light confinement layer and reinforces the current constriction function lost by the reduction in the thickness of the light confinement layer.

Abstract: An AlGaAs-based semiconductor laser 29 is formed on an n-type GaAs substrate 21 and thereafter etching is carried out until reaching an n-type AlGaAs clad layer 23 from the surface. Next, the n-type AlGaAs clad layer 23 is removed by etching with an etchant having selectivity to GaAs. Subsequently, the surface of an n-type GaAs buffer layer 22 is lightly etched. Thus, the n-type GaAs buffer layer 22 of the AlGaAs-based semiconductor laser 29 is left in a slightly abraded state on the n-type GaAs substrate 21, maintaining the flatness of the groundwork layer during growing an AlGaInP-based semiconductor laser 38 at the second time. Therefore, the flatness of the crystals of, in particular, an active layer grown at the second time can be improved, and the poor characteristics of the AlGaInP-based semiconductor laser 38 attributed to the poor flatness of the groundwork can be improved.

Abstract: A manufacturing method for a semiconductor laser in which a ratio of a layer thickness obtained by adding the layer thickness of a p-type GaAs cap layer and the layer thickness of a p-type AlxGa1-xAs (X=0.550) second cladding layer to a layer thickness obtained by adding the layer thickness of a p-type GaAs cap layer and the layer thickness of a p-type AlGaInP second upper cladding layer is identical to a ratio of an etching rate for dry etching of the p-type GaAs cap layer and the p-type AlxGa1-xAs (X=0.550) second cladding layer to an etching rate for dry etching of the p-type GaAs cap layer and the p-type AlGaInP second upper cladding layer.

Abstract: A gallium nitride compound semiconductor light emission device includes: a substrate; an n-type electrode region comprising an n-type transmissive electrode; a gallium nitride compound semiconductor multilayer structure including an active layer; and a p-type electrode region comprising a p-type transmissive electrode. The p-type transmissive electrode and the n-type transmissive electrode transmit light which is generated in the active layer and reflected from the substrate so that the light exits the light emission device.

Abstract: There is provided a semiconductor laser device having on a single substrate a plurality of laser portions each oscillating laser light of a different wavelength, the plurality of laser portions containing different types, respectively, of dopant. There is also provided a method of fabricating a semiconductor laser device, forming on a single substrate a plurality of laser portions each oscillating laser light of a different wavelength, initially forming a laser portion in a crystal growth method and subsequently forming another laser portion in a different crystal growth method.

Abstract: An AlGaAs-based semiconductor laser 29 is formed on an n-type GaAs substrate 21, and thereafter, a non-doped GaAs protective layer 30 is formed. When the n-type substrate 21 is exposed by removing by etching a partial region of the AlGaAs-based semiconductor laser 29, an impurity Zn is prevented from evaporating from a p-type GaAs contact layer 28. The deterioration of the characteristic of contact with a p-type electrode as a consequence of a reduction in the carrier density of the p-type contact layer 28 can be prevented. Furthermore, the impurity evaporated from the p-type contact layer 28 can be prevented from readhering onto the exposed n-type substrate 21. A layer where the n-type GaAs substrate 21 and the readhering impurity are mixed with each other is not formed when an AlGaInP-based semiconductor laser 38 is succeedingly formed, and the reliability in long-term operation can be improved.

Abstract: An n-type AlGaAs cladding layer of a first semiconductor laser 39 to be first formed on an n-type GaAs buffer layer 22 is constructed of a two-layer structure of a second n-type AlxGa1-xAs (x=0.500) cladding layer 23 and a first n-type AlxGa1-xAs (x=0.425) cladding layer 24. With this arrangement, in removing by etching the second n-type cladding layer 23 located on the n-type GaAs buffer layer 22 side with HF, no cloudiness occurs since the Al crystal mixture ratio x of the second n-type cladding layer 23 is 0.500, allowing mirror surface etching to be achieved. Moreover, by virtue of selectivity to GaAs, the etching automatically stops in the n-type GaAs buffer layer 22. Even in the above case, ellipticity can be improved by matching the vertical radiation angle ?? to 36 degrees since the Al crystal mixture ratio x of the first n-type cladding layer 24 located on the AlGaAs multi-quantum well active layer 25 side is 0.425.

Abstract: The solvent-free two-component adhesive composition of the present invention is prepared by a polyol component (A) and a polyisocyanate component (B), wherein the composition comprises at least one polyol component having crystallinity and selected from the group consisting of a polyester polyol, a polyether polyol, a polycarbonate polyol and a polyurethane polyol in an amount of 3 to 50% by weight relative to the total weight of the components (A) and (B). The adhesive composition has the initial viscosity of about 100 to 1,500 mPa·s (in particular, 100 to 1,000 mPa·s) at 70° C. immediately after the components (A) and (B) are mixed together, and the increasing ratio of viscosity after the composition is stood at 70° C. for 10 minutes to the initial viscosity of 120% or less. According to the present invention, a composite laminated film having the good external appearance can be produced simply and effectively.

Abstract: A light confinement layer constructed of a semiconductor that has a refractive index different from that of p-type second cladding layers is formed to a small film thickness of not greater than 2 &mgr;m (about 0.5 &mgr;m) on the whole surface of ridge portions of two semiconductor lasers. Thus, the light confinement layer on the ridge portions is made roughly flat so as to be easily removable by etching. As a result, the exposure of p-type second cladding layers of the ridge portions due to deep etching is prevented to allow the confinement of light into the p-type cladding layers to be stably effected. A dielectric film is formed on the light confinement layer and reinforces the current constriction function lost by the reduction in the thickness of the light confinement layer.

Abstract: There is provided a semiconductor laser device having on a single substrate a plurality of laser portions each oscillating laser light of a different wavelength, the plurality of laser portions containing different types, respectively, of dopant. There is also provided a method of fabricating a semiconductor laser device, forming on a single substrate a plurality of laser portions each oscillating laser light of a different wavelength, initially forming a laser portion in a crystal growth method and subsequently forming another laser portion in a different crystal growth method.

Abstract: An AlGaAs-based semiconductor laser 29 is formed on an n-type GaAs substrate 21 and thereafter etching is carried out until reaching an n-type AlGaAs clad layer 23 from the surface. Next, the n-type AlGaAs clad layer 23 is removed by etching with an etchant having selectivity to GaAs. Subsequently, the surface of an n-type GaAs buffer layer 22 is lightly etched. Thus, the n-type GaAs buffer layer 22 of the AlGaAs-based semiconductor laser 29 is left in a slightly abraded state on the n-type GaAs substrate 21, maintaining the flatness of the groundwork layer during growing an AlGaInP-based semiconductor laser 38 at the second time. Therefore, the flatness of the crystals of, in particular, an active layer grown at the second time can be improved, and the poor characteristics of the AlGaInP-based semiconductor laser 38 attributed to the poor flatness of the groundwork can be improved.

Abstract: An AlGaAs-based semiconductor laser 29 is formed on an n-type GaAs substrate 21, and thereafter, a non-doped GaAs protective layer 30 is formed. When the n-type substrate 21 is exposed by removing by etching a partial region of the AlGaAs-based semiconductor laser 29, an impurity Zn is prevented from evaporating from a p-type GaAs contact layer 28. The deterioration of the characteristic of contact with a p-type electrode as a consequence of a reduction in the carrier density of the p-type contact layer 28 can be prevented. Furthermore, the impurity evaporated from the p-type contact layer 28 can be prevented from readhering onto the exposed n-type substrate 21. A layer where the n-type GaAs substrate 21 and the readhering impurity are mixed with each other is not formed when an AlGaInP-based semiconductor laser 38 is succeedingly formed, and the reliability in long-term operation can be improved.

Abstract: A gallium nitride based light emitting element includes an n type electrode formed on one main surface of an n type gallium nitride substrate, in which the area ratio of the n type electrode with respect to the area of the one main surface is set to be in the range of at least 5% and at most 60%, and the n type electrode includes an n type ohmic electrode layer for introducing current.

Abstract: A semiconductor light-emitting device includes: a substrate; a semiconductor layer including at least one light-emitting region; a metal layer having a light transmitting characteristic; a first fluorescent material layer for converting at least a portion of first light emitted from the light-emitting region into second light having a different wavelength from the first light; and an oxide semiconductor layer formed between the metal layer and the first fluorescent material layer, and having a light-transmitting characteristic.

Abstract: The solvent-free two-component adhesive composition of the present invention comprises a polyol component (A) and a polyisocyanate component (B), and the viscosity of the mixture at 80° C. immediately after the point of time the components (A) and (B) are mixed together is 900 mPa·s or higher. The component (A) may be a polyol having a number average molecular weight of 800 or larger, or a mixture thereof, and the viscosity of the component (B) at 25° C. may be 20,000 mPa·s or higher. The composition may be used for laminating metal foil of 5 to 15 m thickness with a plastic film. By using the composition of the present invention, the occurrence of blocking due to the seepage of the adhesive from metal foil is prevented. The present invention includes a process of lamination using the same.

Abstract: The solvent-free two-component adhesive composition of the present invention is prepared by a polyol component (A) and a polyisocyanate component (B), wherein the composition comprises at least one polyol component having crystallinity and selected from the group consisting of a polyester polyol, a polyether polyol, a polycarbonate polyol and a polyurethane polyol in an amount of 3 to 50% by weight relative to the total weight of the components (A) and (B). The adhesive composition has the initial viscosity of about 100 to 1,500 mPa·s (in particular, 100 to 1,000 mPa·s) at 70° C. immediately after the components (A) and (B) are mixed together, and the increasing ratio of viscosity after the composition is stood at 70° C. for 10 minutes to the initial viscosity of 120% or less. According to the present invention, a composite laminated film having the good external appearance can be produced simply and effectively.

Abstract: The solvent-free two-component adhesive composition of the present invention comprises a polyol component (A) and a polyisocyanate component (B), and the viscosity of the mixture at 80° C. immediately after the point of time the components (A) and (B) are mixed together is 900 mPa·s or higher. The component (A) may be a polyol having a number average molecular weight of 800 or larger, or a mixture thereof, and the viscosity of the component (B) at 25° C. may be 20,000 mPa·s or higher. The composition may be used for laminating metal foil of 5 to 15 m thickness with a plastic film. By using the composition of the present invention, the occurrence of blocking due to the seepage of the adhesive from metal foil is prevented. The present invention includes a process of lamination using the same.

Abstract: A gallium nitride based light emitting element includes an n type electrode formed on one main surface of an n type gallium nitride substrate, in which the area ratio of the n type electrode with respect to the area of the one main surface is set to be in the range of at least 5% and at most 60%, and the n type electrode includes an n type ohmic electrode layer for introducing current.

Abstract: A gallium nitride compound semiconductor light emission device includes: a substrate; an n-type electrode region comprising an n-type transmissive electrode; a gallium nitride compound semiconductor multilayer structure including an active layer; and a p-type electrode region comprising a p-type transmissive electrode. The p-type transmissive electrode and the n-type transmissive electrode transmit light which is generated in the active layer and reflected from the substrate so that the light exits the light emission device.

Abstract: A semiconductor light emitting device includes an insulating substrate; and a layered structure formed on the insulating substrate, the layered structure including at least a light emitting section, a positive electrode section, and a negative electrode section. A portion of the positive electrode section and a portion of the negative electrode section overlap each other via an insulating film.