Abstract: A semiconductor light emitting device includes a substrate, an n-type layer formed of gallium-nitride based compound semiconductor formed on the substrate, and a p-type layer formed of gallium-nitride based compound semiconductor formed on the substrate. Semiconductor overlying layers are constituted by the n-type layer and the p-type layer on the substrate. A light emitting layer is formed together with the n-type and p-type layers in the semiconductor overlying layers to emit light. At least one of the n-type layer and the p-type layer is formed by three or more overlying sublayers including a sublayer of AlyGa1-yN (0<y≦0.5) and a sublayer of AluGa1-uN (0≦u<y). With this structure, the semiconductor light emitting device is almost free from lattice mismatch to thereby enhance electron mobility and hence light emission efficiency even where the overlying semiconductor layers are different in lattice constant from the substrate.

Abstract: A semiconductor layered portion is formed of a gallium-nitride semiconductor overlying a substrate and having an n-type layer and a p-type layer to form a light emitting layer having a pn junction or a doublehetero junction. A gradient layer is provided at an interfacial portion between an lower layer and an upper layer of the semiconductor layered portion, wherein the gradient layer has a composition varied from a composition from said lower layer to a composition of the upper layer. With this structure, a semiconductor light emitting device which is excellent in light emitting efficiency is provided by reducing crystal lattice mismatch between semiconductor layers formed different in lattice constant on a substrate.

Abstract: An n-type layer (3) and a p-type layer (5) which are made of a gallium nitride based compound semiconductor are provided on a substrate (1) so that a light emitting layer forming portion (10) for forming a light emitting layer is provided. A gallium nitride based compound semiconductor layer containing oxygen is used for at least one layer of the light emitting layer forming portion (10). In the case where a buffer layer (2) made of the gallium nitride based compound semiconductor or aluminum nitride is provided between the substrate (1) and the light emitting layer forming portion (10), the buffer layer (2) and/or at least one layer of the light emitting layer forming portion (10) may contain oxygen. By such a structure, crystal defects of the semiconductor layer of the light emitting layer forming portion (10) can be decreased and a luminance can highly be enhanced. Thus, it is possible to obtain a blue color type semiconductor light emitting device having a high luminance.

Abstract: Disclosed is a method of manufacturing a semiconductor light emitting device. Semiconductor overlying layers are formed on a substrate in a state of a wafer so that a light emitting area is provided therein. The semiconductor overlying layers includes first and second conductivity type layers. Part of the semiconductor overlying layers including the first conductivity type layer on a surface thereof is removed so as to expose part of the second conductivity type layer. Electrodes are formed, for each chip, respectively in connection with the surface of the first conductivity type layer and the surface of the exposed second conductivity type layer. The wafer is divided into individual chips. The exposed areas of the second conductivity type semiconductor layer is provided only part of a peripheral area of the chip so that the first conductivity type semiconductor layer is directly separated during dividing the wafer into individual chips.

Abstract: Deposited on a wafer-like substrate for forming a plurality of light emitting device chips is a semiconductor layer laminate with a different property from that of the substrate. Then, electrodes are provided on and in electric connection with a top semiconductor layer of a first conductivity type of the semiconductor layer laminate, and on and in electric connection with a semiconductor layer of a second conductivity type, exposed by locally etching the semiconductor layer laminate, in association with the individual chips. Then, the semiconductor layer laminate is etched at boundary portions between the chips to expose the substrate, and the substrate is broken at the exposed portions into the chips. As the semiconductor layer laminate is etched out at the boundary portions between the chips before breaking the wafer, breaking can be facilitated without damaging the light emitting portions of the semiconductor layer laminate. This helps provide high-performance semiconductor light emitting devices.

Abstract: A semiconductor light emitting device has semiconductor layers including a first conductivity type semiconductor layer and a second conductivity type semiconductor layer formed on a substrate. A first electrode is formed in electrical connection with the first conductivity type semiconductor layer on a surface side of the semiconductor layers. The second conductivity type semiconductor layer is exposed by partly etch-removing an end portion of the semiconductor layers. A second electrode is provided in electrical connection with the exposed second conductivity type layer. The first and second electrodes are formed such that the electrodes are in parallel, in plan form, with each other at opposite portions thereof. As a result, the current path is constant in electric resistance, providing a semiconductor light emitting device that is constant in brightness, long in service life and high in brightness.

Abstract: A semiconductor light emitting device incorporates therein with (a) a light emitting portion formed by semiconductor overlying layers including a first conductivity layer and a second conductivity layer in order to a light emitting layer, and (b) a protecting element portion provided in electrical connection between said first conductivity type layer and said second conductivity type layer so that said light emitting portion is protected against at least a reverse voltage applied to said light emitting portion. The light emitting portion and the protecting element portion can be formed by separate chips or in one chip having the both. They are formed into a lamp-type or chip-type light emitting device. The incorporation of the protecting element increase the reverse-voltage resistance for a compound semiconductor, such as galium-itride or the like, that is less resistive to reverse voltages applied.

Abstract: A semiconductor light emitting device includes a substrate and semiconductor overlying layers formed on the substrate. A light emitting layer is formed in the semiconductor layer so as to emit light. The substrate is transmittable of the light emitted by the light emitting layer. A light reflecting layer is formed on a part of a back surface of the substrate. As a result, a semiconductor light emitting device is obtainable by easily dividing a wafer having thereon a light emitting film through recognizing, from a wafer back side, semiconductor layer chip pattern formed overlying the main surface of the wafer.