Rohm Co., Ltd.

Other

Pioneer Corporation

Rohm Gmbh

Masayuki Sonobe

Tsuyoshi Tsutsui

Yukio Shakuda

Shunji Nakata

Norikazu Itoh

Norikazu Ito

Mitsuhiko Sakai

Tetsuhiro Tanabe

Kazuaki Tsutsumi

Toshio Nishida

Atsushi Yamaguchi

Ken Nakahara

Hiroyuki Ota

Yoshinori Kimura

Shinji Isokawa

Atsushi Watanabe

Yasuo Nakanishi

Yoshikazu Nakagawa

Hidekazu Toda

Hirokazu Asahara

Tetsuo Fujii

Shinichi Tamai

A semiconductor light emitting device and a fabrication method for the semiconductor light emitting device whose outward luminous efficiency improved are provided and the semiconductor light emitting device includes a substrate; a protective film placed on the substrate; an n-type semiconductor layer which is placed on the substrate pinched by a protective film and on the protective film, and is doped with an n-type impurity; an active layer placed on the n-type semiconductor layer, and a p-type semiconductor layer placed on the active layer and is doped with a p-type impurity.

Light emitting semiconductor device having an improved outward luminosity efficiency and fabrication method for the light emitting semiconductor device

A semiconductor light emitting device of the present invention includes a substrate (), an n-GaN layer () supported by the substrate (), a p-GaN layer () which is located farther from the substrate () than the n-GaN layer () is, an active layer () formed between the n-GaN layer () and the p-GaN layer () and containing InGaN, a sublimation preventing layer () formed between the active layer () and the p-GaN layer () and containing InGaN, and an In composition gradient layer () sandwiched between the sublimation preventing layer () and the p-GaN layer () and having such In composition ratio gradient that the In composition ratio decreases in the thickness direction toward the p-GaN layer ().

Semiconductor light-emitting device and process for producing the same

There are provided a nitride semiconductor light emitting device having a structure enabling enhanced external quantum efficiency by effectively taking out light which is apt to repeat total reflection within a semiconductor lamination portion and a substrate and attenuate, and a method for manufacturing the same. A semiconductor lamination portion () including a first conductivity type layer and a second conductivity type layer, made of nitride semiconductor, is provided on a surface of the substrate () made of, for example, sapphire or the like. A first electrode (for example, p-side electrode ()) is provided electrically connected to the first conductivity type layer (for example, p-type layer ()) on a surface side of the semiconductor lamination portion (), and a second electrode (for example, n-side electrode ()) is provided electrically connected to the second conductivity type layer (for example, n-type layer ()). A part of the semiconductor lamination portion () is removed at a surrounding region of a chip of the semiconductor lamination portion () by etching so that column portions () stand side by side by leaving the semiconductor lamination portion without etching, and the n-type layer () expose around the column portions ().

Semiconductor light emitting device and method for manufacturing the same

There is provided a nitride semiconductor light emitting device having a light reflection layer capable of preventing reflectivity from lowering and luminance from lowering due to deterioration of quality of an active layer. A nitride semiconductor laser includes at least a light emitting layer forming portion () provided on a first light reflection layer () provided on a substrate (). The first light reflection layer () is formed with laminating a low refractivity layer () and a high refractivity layer () which have a different refractivity from each other, and the low refractivity layer () of the first light reflection layer is formed with a single layer structure of an AlGaN layer (0&#x2266;x&#x2266;1), and the high refractivity layer () of the first light reflection layer is formed with a multi layer structure formed by laminating alternately an AlGaN layer (0&#x2266;y&#x2266;0.5 and y&#x3c;x) or an InGaN layer (0&#x3c;t&#x2266;0.5) and an InGaN layer (0&#x3c;u&#x2266;1 and t&#x3c;u).

Nitride semiconductor light emitting device

There is provided a highly reliable semiconductor light emitting device even in using for street lamps or traffic signals, which can be used in place of electric lamps or fluorescent lamps by protecting from surges such as static electricity or the like. A plurality of light emitting units () are formed, by forming a semiconductor lamination portion by laminating semiconductor layers on a substrate so as to form a light emitting layer, by electrically separating the semiconductor lamination portion into a plurality, and by providing a pair of electrodes () and (). The light emitting units () are respectively connected in series and/or in parallel with wiring films (). An inductor () absorbing surges is connected, in series, to the plurality of light emitting units () connected in series between electrode pads () and () connected to an external power source. For an example, the inductor () is formed by arranging the plurality of light emitting units () in a whirl shape.

Semiconductor light emitting device

A semiconductor light emitting element array includes a substrate made of SiC and having a first surface and a second surface opposite to the first surface. The array also includes a plurality of semiconductor light emitting elements supported by the first surface of the substrate. Each of the light emitting elements includes an n-type semiconductor layer, an active layer, and a p-type semiconductor layer. The second surface of the substrate serves as a light emitting surface, from which light produced by the light emitting elements is emitted out.

Semiconductor light emitting element array illuminator using the same

A semiconductor light emitting device includes a semiconductor light emitting portion having a first contact layer of a first conductivity, a second contact layer of a second conductivity and an active layer sandwiched between the first and second contact layers. The device further includes a transparent electrode which substantially entirely covers a surface of the second contact layer in ohmic contact with the surface of the second contact layer and is transparent to a wavelength of light emitted from the semiconductor light emitting portion, and a metal reflection film which is opposed to substantially the entire surface of the transparent electrode and electrically connected to the transparent electrode, and reflects the light emitted from the semiconductor light emitting portion and passing through the transparent electrode toward the semiconductor light emitting portion.

A III-V nitride semiconductor laser device demonstrates an excellent emission characteristic without an increase in production cost. The refractive index of a p-side optical guiding layer is larger than that of an n-side guide layer.

III-V nitride semiconductor laser device

A nitride semiconductor device is composed of Group III nitride semiconductors. The device includes an active layer, and a barrier layer made from a predetermined material and provided adjacent to the active layer. The barrier layer has a greater band-gap than that of the active layer. The device also includes a barrier portion formed of the predetermined material for surrounding a threading dislocation in the active layer. The barrier portion has a vertex. The device also includes a semiconductor layer having an impurity concentration ranging from 1E16/cc to 1E17/cc in which the vertex is placed.

Nitride semiconductor device and method for manufacturing the same

A first GaN layer ( ) is formed on a substrate ( ), mask layer ( ) having opening parts ( ) are formed thereon, a second GaN layer ( ) is selectively grown in the lateral direction from the opening parts on the mask layer, and further a nitride type compound semiconductor layered part ( ) is so laminated as to form a light emitting layer. Recessed parts ( ) are formed in the upper face side of the mask layer. In other words, owing to the recessed parts in the upper face side of the mask layer, the second GaN type compound semiconductor layer ( ) is grown as to form approximately parallel gap ( ) between the bottom face of the second GaN type compound semiconductor layer and the mask layer. Further, it is preferable for the mask to be formed in a manner that the opening parts for exposing the seeds are not arranged only continuous in one single direction in the entire surface of the wafer type substrate. Consequently, a nitride type compound semiconductor light emitting device can be obtained while being provided with a low dislocation density and excellent light emitting efficiency and especially a semiconductor laser with a lowered threshold current value can be obtained.

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 Al,Ga,N (0<y&lE;0.5) and a sublayer of Al,Ga,N (0&lE;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.

Fabrication of semiconductor light emitting device

Semiconductor layers forming a light emitting layer and including an n-type layer and p-type layer are formed onto a substrate, then the n-type layer is exposed by removing a part of the laminated semiconductor layers. p-side electrode and n-side electrode are then respectively formed on the p-type layer on the surface of the laminated semiconductor layers and the exposed n-type layer, respectively in an electrically connected manner, followed by dicing of the substrate from the exposed n-type layer to the substrate at portions at which breaking of the substrate is performed. Then a protection film is provided on the entire surface of the laminated semiconductor layers as to expose the p-side and n-side electrodes, and breaking of the substrate is performed at dicing portions into individual chips. Consequently, semiconductor light emitting devices can be obtained by breaking the wafer into individual chips without etching the protection film and without damaging the protection film at the time of breaking. Also, the light emitting devices can be improved.

Method for manufacturing semiconductor light emitting device

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.

Semiconductor light emitting device and method of manufacturing the same

An n-type layer (,) and a p-type layer (,) which are made of a gallium nitride based compound semiconductor are provided on a substrate (,) so that a light emitting layer forming portion (,) 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 (,). In the case where a buffer layer (,) made of the gallium nitride based compound semiconductor or aluminum nitride is provided between the substrate (,) and the light emitting layer forming portion (,), the buffer layer (,) and/or at least one layer of the light emitting layer forming portion (,) may contain oxygen. By such a structure, crystal defects of the semiconductor layer of the light emitting layer forming portion (,) 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.

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Kyoto, Japan

Masayuki Sonobe