Abstract: An InGaN active layer is formed on a sapphire substrate. A p-side electrode is formed on the InGaN active layer to supply an electric current to this InGaN active layer. The p-side electrode includes {circle over (1)} an Ni layer for forming an ohmic contact with a p-GaN layer, {circle over (2)} an Mo layer having a barrier function of preventing diffusion of impurities, {circle over (3)} an Al layer as a high-reflection electrode, {circle over (4)} a Ti layer having a barrier function, and {circle over (5)} an Au layer for improving the contact with a submount on a lead frame. The p-side electrode having this five-layered structure realizes an ohmic contact and high reflectance at the same time.

Abstract: An image display device including a light emission section which emits light to an intensity adjusting section and a wavelength conversion section which change the intensity and wavelength of the emitted light. Phosphors and phosphor like materials are employed in wavelength conversion and a liquid crystal is employed for the light adjustment. The light emission device may include plural semiconductor light emitting elements having a different wavelength ranges such as diodes stacked in a compact and predetermined order such that wavelengths of light from each diode are emitted from the light emitting elements.

Abstract: Efficiency of leading out light released from an active layer, i.e. the external quantum efficiency, can be improved remarkably by processing a light lead-out surface to have an embossment. A layer containing a p-type dopant like magnesium (Mg) is deposited near the surface of a p-type GaN layer to diffuse it there, and a p-side electrode is made on the p-type GaN layer after removing the deposited layer. This results in ensuring ohmic contact with the p-side electrode, preventing exfoliation of the electrode and improving the reliability.

Abstract: Efficiency of leading out light released from an active layer, i.e. the external quantum efficiency, can be improved remarkably by processing a light lead-out surface to have an embossment. A layer containing a p-type dopant like magnesium (Mg) is deposited near the surface of a p-type GaN layer to diffuse it there, and a p-side electrode is made on the p-type GaN layer after removing the deposited layer. This results in ensuring ohmic contact with the p-side electrode, preventing exfoliation of the electrode and improving the reliability.

Abstract: An electrode of a metal, which is one of Group IV and VI elements, is deposited on an n-type InxAlyGa1−x−yN layer. Alternatively, after an electrode material of carbon, germanium), selenium, rhodium, tellurium, iridium, zirconium, hafnium, copper, titanium nitride, tungsten nitride, molybdenum or titanium silicide, is deposited on an n-type InxAlyGa1−x−yN layer or a p-type InxAlyGa1−x−yN layer, an impurity for increasing the carrier concentration of the semiconductor layer is ion-implanted, and the annealing is carried out. Thus, it is possible to provide a light emitting semiconductor device, which has a low contact resistance and a sufficient bond strength to the InxAlyGa1−x−yN layer while maintaining the crystallinity of the InxAlyGa1−x−yN layer.

Abstract: An InGaN active layer is formed on a sapphire substrate. A p-side electrode is formed on the InGaN active layer to supply an electric current to this InGaN active layer. The p-side electrode includes {circle over (1)} an Ni layer for forming an ohmic contact with a p-GaN layer, {circle over (2)} an Mo layer having a barrier function of preventing diffusion of impurities, {circle over (3)} an Al layer as a high-reflection electrode, {circle over (4)} a Ti layer having a barrier function, and {circle over (5)} an Au layer for improving the contact with a submount on a lead frame. The p-side electrode having this five-layered structure realizes an ohmic contact and high reflectance at the same time.

Abstract: A compound semiconductor light emitting element includes a light emitting region formed by a pn-junction between a first compound semiconductor layer of a first conductivity type and a second compound semiconductor layer of a second conductivity type. A first electrode is connected to the first compound semiconductor layer and is isolated from the second compound semiconductor layer. A current spreading layer is formed on the second compound semiconductor layer and a block is formed on the second compound semiconductor layer. A second electrode is formed on the block and is connected to the current spreading layer.

Abstract: An electrode of a metal, which is one of Group IV and VI elements, is deposited on an n-type InxAlyGa1-x-yN layer. Alternatively, after an electrode material of carbon, germanium), selenium, rhodium, tellurium, iridium, zirconium, hafnium, copper, titanium nitride, tungsten nitride, molybdenum or titanium silicide, is deposited on an n-type InxAlyGa1-x-yN layer or a p-type InxAlyGa1-x-yN layer, an impurity for increasing the carrier concentration of the semiconductor layer is ion-implanted, and the annealing is carried out. Thus, it is possible to provide a light emitting semiconductor device, which has a low contact resistance and a sufficient bond strength to the InxAlyGa1-x-yN layer while maintaining the crystallinity of the InxAlyGa1-x-yN layer.

Abstract: An electrode of a metal, which is one of Group IV and VI elements, is deposited on an n-type InxAlyGa1−x−yN layer. Alternatively, after an electrode material of carbon, germanium), selenium, rhodium, tellurium, iridium, zirconium, hafnium, copper, titanium nitride, tungsten nitride, molybdenum or titanium silicide, is deposited on an n-type InxAlyGa1−x−yN layer or a p-type InxAlyGa1−x−yN layer, an impurity for increasing the carrier concentration of the semiconductor layer is ion-implanted, and the annealing is carried out. Thus, it is possible to provide a light emitting semiconductor device, which has a low contact resistance and a sufficient bond strength to the InxAlyGa1−x−yN layer while maintaining the crystallinity of the InxAlyGa1−x−yN layer.

Abstract: A process for preparing an aqueous dispersion coating material containing a resin component having a softening temperature of from 10 to 250° C., which comprises: (1) a step of mixing various starting materials which will be coating film-constituting components, to obtain a blend material, (2) a step of melting and kneading the blend material at a temperature of at least the softening temperature of said resin component, to obtain a homogenized material, (3) a step of cooling and solidifying the homogenized material, followed by crushing, to obtain coarse particles, and (4) a step of wet-pulverizing the coarse particles in an aqueous dispersant, to obtain an aqueous dispersion coating material containing fine particles having an average particle size of at most 10 &mgr;m.

Abstract: A nitride compound semiconductor light emitting element is made by stacking a metal layer made of one of elements: palladium (Pd), scandium (Sc), vanadium (V), zirconium (Zr), hafnium (Hf), tantalum (Ta), rhodium (Rh), iridium (Ir), cobalt (Co) and copper (Cu), and another metal layer made of one of elements: titanium (Ti), nickel (Ni), molybdenum (Mo), tungsten (W) and magnesium (Mg), to increase the adhesive strength of its electrodes with a semiconductor layer, reduce the contact resistance of the electrodes to improve the ohmic characteristics, and improve the external quantum efficiency by combination of thin-film metals with a transparent electrode.

Abstract: A compound semiconductor light emitting element includes a light emitting region formed by a pn-junction between a first compound semiconductor layer of a first conductivity type and a second compound semiconductor layer of a second conductivity type. A first electrode is connected to the first compound semiconductor layer and is isolated from the second compund semiconductor layer. A current spreading layer is formed on the second compound semiconductor layer and a block is formed on the second compound semiconductor layer. A second electrode is formed on the block and is connected to the current spreading layer.

Abstract: A semiconductor laser is formed from a gallium nitride-based compound semiconductor material, and has a double-heterostructure portion obtained by sandwiching an active layer between an n-type cladding layer and a p-type cladding layer on a sapphire substrate. The double-heterostructure portion is formed into a mesa shape on the sapphire substrate via a GaN buffer layer. The two sides of this mesa structure are buried with GaN current blocking layers.

Abstract: For providing an avalanche photodiode having a good guard ring effect and a high speed response, a body of semiconductor materials is prepared, which includes a window layer of n-type InP epitaxially grown on an avalanche multiplication layer of n.sup.+ -type InP. The window layer is selectively removed so as to expose the avalanche multiplication layer, thereby providing a recessed portion therein. After a p-type impurity is selectively introduced into the window layer to form a guard ring therein, a p-type impurity is selectively introduced into both the exposed avalanche multiplication layer and the guard ring to provide a PN junction therein.

Abstract: The present invention relates to a process for forming a multi-layer coating including at least two coating layers by performing the oven drying step at one time, which comprises coating at least partially the surface of the substrate with a powder coating composition, then applying a slurry paint composition comprising synthetic resin particles dispersed in an aqueous medium and then heating.

Abstract: This invention relates to an aqueous dispersion type coating composition comprising a homogeneous mixture of an aqueous medium, synthetic resin particles and a scaly aluminum pigment.

Abstract: The present invention relates to a process for forming a multi-layer coating including at least two coating layers by performing the oven drying step at one time, which comprises applying a slurry paint comprising synthetic resin particles dispersed in an aqueous medium, to an undried coating which is in the non-fluid state but is not completely dried.