Toyoda Gosei Co., Ltd.

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Research Development Corporation of Japan

Shinya Asami

Hiroshi Watanabe

Naoki Shibata

Jun Ito

Masayoshi Koike

Toshiaki Chiyo

Shizuyo Asami

Norikatsu Koide

Masanobu Senda

Junichi Umezaki

Seiji Nagai

Shiro Yamasaki

Hisaki Kato

Michinari Sassa

Shiro Yamazaki

Katsuhide Manabe

Makoto Asai

Takahiro Kozawa

A Group III nitride compound semiconductor includes a multiple layer structure having an emission layer between an n-type cladding layer and a p-type cladding layer. The n-type cladding layer may be below the emission layer, having been formed on another n-type layer which was formed over a buffer Layer and a sapphire substrate. The emission layer has a thickness which is wider than the diffusion length of holes within the emission layer. The n-type cladding layer is doped with a donor impurity and has a lattice constant Substantially equal to a lattice constant of the emission layer. The p-type cladding layer is doped with an acceptor impurity and has a forbidden band sufficiently wider than the forbidden band of the emission layer in ordor to confine electrons injected into the emission layer.

Light-emitting semiconductor device using Group III nitride compound

A barrier layer made of AlGaN (0&#x3c;x&#x2266;0.18) is formed in a light-emitting semiconductor device using gallium nitride compound having a multi quantum-well (MQW) structure. By controlling a composition ratio x of aluminum (Al) or thickness of the barrier layer, luminous intensity of the device is improved. An n-cladding layer made of AlGaN (0&#x3c;x&#x2266;0.06) is formed in a light-emitting semiconductor device using gallium nitride compound. By controlling a composition ratio x of aluminum or thickness of the n-cladding layer, luminous intensity of the device is improved. A p-type layer and an n-type layer are formed in a light-emitting semiconductor device using gallium nitride compound having a double-hetero junction structure. By controlling a ratio of a hole concentration of the p-type layer and an electron concentration of the n-type layer approximates to 1, luminous intensity of the device is improved.

Light-emitting semiconductor device using gallium nitride compound semiconductor

A Group III nitride compound semiconductor light-emitting device includes a multilayer having a quantum well structure containing an InGaN well layer and an AlGaN barrier layer. The film thickness, growth rate and growth temperature of the InGaN layer as the well layer and the film thickness of the AlGaN layer as the barrier layer are controlled to be optimized to thereby improve an output of the light-emitting device.

III group nitride compound semiconductor luminescent element

A group III nitride compound semiconductor device is produced according to the following manner. A separation layer made of a material which prevents group III nitride compound semiconductors from being grown thereon is formed on a substrate. Group III nitride compound semiconductors is grown on a surface of the substrate uncovered with the separation layer while keeping the uncovered substrate surface separated by the separation layer.

Group III nitride compound semiconductor device and method for producing the same

A first group III nitride compound layer, which is formed on a substrate by a method not using metal organic compounds as raw materials, is heated in an atmosphere of a mixture gas containing a hydrogen or nitrogen gas and an ammonia gas, so that the crystallinity of a second group III nitride compound semiconductor layer formed on the first group III nitride compound layer is improved. When the first group III nitride compound layer is formed on a substrate by a sputtering method, the thickness of the first group III nitride compound layer is set to be in a range of from 50 &#x212b; to 3000 &#x212b;.

Group III nitride compound semiconductor device and method of producing the same

A group III nitride compound semiconductor device has a substrate and an AlN single crystal layer formed on the substrate. The AlN single crystal layer has a thickness of from 0.5 to 3 &#x3bc;m and has a substantially flat surface. The half-value width of an X-ray rocking curve of the AlN single crystal layer is not longer than 50 sec. In another device, a group III nitride compound semiconductor layer having a thickness of from 0.01 to 3.2 &#x3bc;m is grown at a temperature of from 1000 to 1180&#xb0; C. on a sapphire substrate having a surface nitride layer having a thickness of not larger than 300 &#x212b;.

Group III nitride compound semiconductor device and producing method therefor

An undercoat layer inclusive of a metal nitride layer is formed on a substrate. Group III nitride compound semiconductor layers are formed on the undercoat layer continuously.

Group III nitride compound semiconductor device

An AlN layer having a surface of a texture structure is formed on a sapphire substrate. Then, a growth suppressing material layer is formed on the AlN layer so that the AlN layer is partially exposed to the outside. Then, group III nitride compound semiconductor layers are grown on the AlN layer and on the growth suppressing material layer by execution of an epitaxial lateral overgrowth method. Thus, a group III nitride compound semiconductor device is produced. An undercoat layer having convex portions each shaped like a truncated hexagonal pyramid is formed on a substrate. Group III nitride compound semiconductor layers having a device function are laminated successively on the undercoat layer.

In a group III nitride compound semiconductor light-emitting device, a light-emitting layer having a portion where an InGaN layer is interposed between AlGaN layers on both sides thereof is employed. By controlling the thickness, growth rate and growth temperature of InGaN layer which is a well layer and the thickness of AlGaN layer which is a barrier layer so that they are optimized, the output of the light-emitting device is enhanced.

Group III nitride compound semiconductor light-emitting device which emits light having a wavelength in a range from 360 to 550 NM

In a method of manufacturing a semiconductor light-emitting device involving the steps of: forming a first semiconductor layer; forming a light-emitting layer of superlattice structure by laminating a barrier layer being made of In Ga N (Y1&gE;0) and a quantum well layer being made of In Ga N (Y2>Y1 and Y2>0) on the first semiconductor layer; and forming a second semiconductor layer on the light-emitting layer, an uppermost barrier layer, which will become an uppermost layer of the light-emitting layer, is made thicker than the other barrier layers. Further, at the time of forming the second semiconductor layer, an upper surface of such uppermost barrier layer is caused to disappear so that the thickness of the uppermost barrier layer becomes substantially equal to those of the other barrier layers.

Semiconductor light-emitting device and manufacturing method thereof

A first group III nitride compound layer, which is formed on a substrate by a method not using metal organic compounds as raw materials, is heated in an atmosphere of a mixture gas containing a hydrogen or nitrogen gas and an ammonia gas, so that the crystallinity of a second group III nitride compound semiconductor layer formed on the first group III nitride compound layer is improved. When the first group III nitride compound layer is formed on a substrate by a sputtering method, the thickness of the first group III nitride compound layer is set to be in a range of from 50 &angst; to 3000 &angst;.

An emission layer ( ) for a light source device is formed to have a multi-layer structure, doped with an acceptor and a donor impurity. The multi-layer structure may include a quantum well (QW) structure or a multi quantum well (MQW) structure ( ). With such a structure, a peak wavelength of the light source can be controlled, because the distances between atoms of the acceptor and the donor impurities are widened. Several arrangements can be made by, e.g., altering the thickness of each composite layer of the multi-layer structure, altering their composition ratio, forming undoped layer between the impurity doped layers, and so forth. Further, luminous intensity of ultra violet color can be improved, because doping the donor impurity and the acceptor impurity realizes a donor-acceptor emission mechanism and abundant carriers. Several arrangements can be made by, e.g., optimizing the materials of the composite layers, optimizing their composition ratios, optimizing their lattice constants, and so forth to further enhance the luminous intensity of the light source.

Light-emitting semiconductor device using group III nitride compound

A method of manufacturing a group III nitride compound semiconductor device, includes providing a substrate, forming a group III nitride compound semiconductor layer having a device function, and forming an undercoat layer between the substrate and the group III nitride semiconductor layer, the undercoat layer having a surface of a peak and trough structure.

Method for manufacturing group III nitride compound semiconductor device

A group III nitride compound semiconductor device has a substrate and an AlN single crystal layer formed on the substrate. The AlN single crystal layer has a thickness of from 0.5 to 3 &mgr;m and has a substantially flat surface. The half-value width of an X-ray rocking curve of the AlN single crystal layer is not longer than 50 sec. In another device, a group III nitride compound semiconductor layer having a thickness of from 0.01 to 3.2 &mgr;m is grown at a temperature of from 1000 to 1180&deg; C. on a sapphire substrate having a surface nitride layer having a thickness of not larger than 300 &angst;.

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Aichi-ken, Japan

Shinya Asami