Toyoda Gosei Co., Ltd.

Masashi Deguchi

Shingo Totani

Masao Kamiya

Naoki Nakajo

Miki Moriyama

Kosuke Yahata

Takashi Mizobuchi

Takahiro Mori

A face-up-type Group III nitride semiconductor light-emitting device includes a growth substrate, an n-type layer, a light-emitting layer, a p-type layer, an n-electrode including a bonding portion and a wiring portion, a p-electrode including a bonding portion and a wiring portion, and a first insulating film. The n-type layer, the light-emitting layer, and the p-type layer are sequentially stacked on the growth substrate, and the n-electrode and the p-electrode are formed on the first insulating film. A groove having a depth extending from a top surface of the p-type layer to the n-type layer is formed in at least one region selected from a region directly below the wiring portion of the n-electrode and a region directly below the wiring portion of the p-electrode. The wiring portion, which is formed in the groove, is located at a level lower than that of the light-emitting layer.

Group III nitride semiconductor light-emitting device

A light emitting element includes a semiconductor laminate structure including a first semiconductor layer of a first conductivity type, a light emitting layer, and a second semiconductor layer of a second conductivity type different from the first conductivity type, a part of the second semiconductor layer and the light emitting layer being removed to expose a part of the first semiconductor layer, a first reflecting layer located on the semiconductor laminate structure and including an opening, the opening being formed in the exposed part of the first semiconductor layer, a transparent wiring electrode for carrier injection into the first semiconductor layer or the second semiconductor layer through the opening, and a second reflecting layer formed on the transparent wiring electrode and covering a part of the opening so as to reflect light emitted from the light emitting layer and passing through the opening back to the first semiconductor layer.

Light emitting element

A semiconductor light emitting element includes a semiconductor multilayer structure including a first conductive type layer, a second conductive type layer and a light emitting layer sandwiched between the first conductive type layer and the second conductive type layer, a first transparent electrode formed on the second conductive type layer, a reflecting layer formed on the first transparent electrode, and including a smaller area than the first transparent electrode, a second transparent electrode formed on the first transparent electrode so as to cover the reflecting layer, and a pad electrode formed on the second transparent electrode and in a region above the reflecting layer.

Semiconductor light emitting element

A method for manufacturing a semiconductor light emitting element comprises steps of forming a semiconductor layer composed of a Group III nitride based compound semiconductor on a principal surface of a substrate; forming a transparent conductive metal oxide film on the semiconductor layer; forming an electrode above the transparent conductive metal oxide film; forming a mask layer for covering a part of the transparent conductive metal oxide film; and heat treating the transparent conductive metal oxide film having the mask layer formed thereon in an oxygen-containing atmosphere; wherein, in the heat treatment step, an oxygen concentration of a remaining part of the transparent conductive metal oxide film which is not covered by the mask layer is made higher than an oxygen concentration of a part of the transparent conductive metal oxide film which is covered by the mask layer.

Semiconductor light emitting element and method for manufacturing the same

Sample A is produced by sequentially forming a first insulating film of SiOand a reflective film on a sapphire substrate. Sample B is produced by sequentially forming a first insulating film of SiO, a reflective film, and a second insulating film of SiOon a sapphire substrate. In both samples A and B, the reflectance of the reflective film was measured at a wavelength of 450 nm before and after heat treatment. Heat treatment was performed at 600&#xb0; C. for three minutes. As shown in FIG., in Al/Ag/Al where Al has a thickness of 1 &#x212b; to 30 &#x212b;, Ag/Al where Al has a thickness of 20 &#x212b;, and Al/Ag/Al/Ag/Al where Al has a thickness of 20 &#x212b;, the reflectance was 95% or more, which is equivalent to or higher than that of Ag even after the heat treatment.

Method for producing group III nitride semiconductor light-emitting device

A semiconductor light emitting element includes a semiconductor multilayer structure including a first conductive type layer, a second conductive type layer, and a light emitting layer sandwiched between the first conductive type layer and the second conductive type layer, and a reflecting layer formed on the second conductive type layer for reflecting the light emitted from the light emitting layer. The light is extracted in a direction from the light emitting layer toward the first conductive type layer. The first conductive type layer includes a concavo-convex region on a surface thereof not opposite to the light emitting layer, for changing a path of light, and at least a part of the reflecting layer is formed extending to right above an edge of the concavo-convex region.

A Group III nitride semiconductor light-emitting device, includes a groove having a depth extending from the top surface of a p-type layer to an n-type layer is provided in a region overlapping (in plan view) with the wiring portion of an n-electrode or the wiring portion of a p-electrode. An insulating film is provided so as to continuously cover the side surfaces and bottom surface of the groove, the p-type layer, and an ITO electrode. The insulating film incorporates therein reflective films in regions directly below the n-electrode and the p-electrode (on the side of a sapphire substrate). The reflective films in regions directly below the wiring portion of the n-electrode and the wiring portion of the p-electrode are located at a level lower than that of a light-emitting layer. The n-electrode and the p-electrode are covered with an additional insulating film.

A light emitting element includes a semiconductor laminate structure including a first semiconductor layer of a first conductivity type, a light emitting layer, and a second semiconductor layer of a second conductivity type different from the first conductivity type, a part of the second semiconductor layer and the light emitting layer being removed to expose a part of the first semiconductor layer, a first reflecting layer on the semiconductor laminate structure and including an opening, the opening being formed in the exposed part of the first semiconductor layer, a transparent wiring electrode for carrier injection into the first semiconductor layer or the second semiconductor layer through the opening, a second reflecting layer formed on the transparent wiring electrode and covering a part of the opening so as to reflect light emitted from the light emitting layer and passing through the opening back to the first semiconductor layer.

A reflective film including Ag of an Ag alloy is patterned in a uniform thickness without decreasing reflectivity. The reflective film is formed on the entire surface of a first insulating film by sputtering, vacuum deposition or the like, and a barrier metal film having a given pattern is formed on the reflective film by a lift-off method. The reflective film is wet etched using a silver etching liquid. The barrier metal film is not wet etched by the silver etching liquid, and therefore functions as a mask, and the reflective film in a region on which the barrier metal film has been formed remains not etched. As a result, the reflective film having a desired patter can uniformly be formed on the first insulating film.

Method for producing group III nitride semiconductor light emitting element

A semiconductor light-emitting element includes a semiconductor laminated structure including a light-emitting layer sandwiched between first and second conductivity type layers for extracting an emitted light from the light-emitting layer on a side of the second conductivity type layer, a transparent electrode in ohmic contact with the second conductivity type layer, an insulation layer formed on the transparent electrode, an upper electrode for wire bonding formed on the insulation layer, a lower electrode that penetrates the insulation layer, is in ohmic contact with the transparent electrode and the electrode for wire bonding, and has an area smaller than that of the upper electrode in top view, and a reflective portion for reflecting at least a portion of light transmitted through a region of the transparent electrode not in contact with the lower electrode.

Semiconductor light-emitting element

A first intermediate electrodeis a plural number of electrodes connecting to plural electrode forming parts formed in plural places, respectively on the surface of a first semiconductor layer. A second intermediate electrodeis a plural number of electrodes connecting to plural places of a transparent electrically conductive film, respectively. A first electrodeconnects a plural number of the first intermediate electrodesto each other, and a second electrodeconnects a plural number of the second intermediate electrodesto each other. The transparent electrically conductive filmis formed thin in a region A where a distance between the first intermediate electrode and the second intermediate electrode is the shortest, as compared with other regions.

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Kiyosu, Japan

Masashi Deguchi