A nitride semiconductor light-emitting device has an active layer of a single-quantum well structure or multi-quantum well made of a nitride semiconductor containing indium and gallium. A first p-type clad layer made of a p-type nitride semiconductor containing aluminum and gallium is provided in contact with one surface of the active layer. A second p-type clad layer made of a p-type nitride semiconductor containing aluminum and gallium is provided on the first p-type clad layer. The second p-type clad layer has a larger band gap than that of the first p-type clad layer. An n-type semiconductor layer is provided in contact with the other surface of the active layer.

Nitride semiconductor light emitting device

The light-radiating semiconductor component has a radiation-emitting semiconductor body and a luminescence conversion element. The semiconductor body emits radiation in the ultraviolet, blue and/or green spectral region and the luminescence conversion element converts a portion of the radiation into radiation of a longer wavelength. This makes it possible to produce light-emitting diodes which radiate polychromatic light, in particular white light, with only a single light-emitting semiconductor body. A particularly preferred luminescence conversion dye is YAG:Ce.

Light-radiating semiconductor component with a luminescence conversion element

Provided is a light emitting diode (LED) manufactured by using a wafer bonding method and a method of manufacturing a LED by using a wafer bonding method. The wafer bonding method may include interposing a stress relaxation layer (33) formed of a metal between a semiconductor layer (20) and a bonding substrate (31). When the stress relaxation layer is used, stress between the bonding substrate and a growth substrate may be offset due to the flexibility of metal, and accordingly, bending or warpage of the bonding substrate may be reduced or prevented.

Light-emitting device and method of manufacturing the same

A nitride semiconductor device including a light emitting device comprises a n-type region of one or more nitride semiconductor layers having n-type conductivity, a p-type region of one or more nitride semiconductor layers having p-type conductivity and an active layer between the n-type region and the p-type region. In such devices, there is provided with a super lattice layer comprising first layers and second layers which are nitride semiconductors having a different composition respectively. The super lattice structure makes working current and voltage of the device lowered, resulting in realization of more efficient devices.

Nitride semiconductor device

A light emitting diode (20) emits in the blue portion of the visible spectrum and is characterized by an extended lifetime. The light emitting diode comprises a conductive silicon carbide substrate (21); an ohmic contact (22) to the silicon carbide substrate; a conductive buffer layer (23) on the substrate and selected from the group consisting of gallium nitride, aluminum nitride, indium nitride, ternary Group III nitrides having the formula AxB1-xN, where A and B are Group III elements and where x is zero, one, or a fraction between zero and one, and alloys of silicon carbide with such ternary Group III nitrides; and a double heterostructure (24) including a p-n junction on the buffer layer in which the active (25) and heterostructure layers (26, 27) are selected from the group consisting of binary Group III nitrides and ternary Group III nitrides.

Vertical geometry light emitting diode with group iii nitride active layer and extended lifetime

The present disclosure relates to a semiconductor light-emitting element, which comprises: a first light-emitting part, a second light-emitting part, and a third light-emitting part, wherein each of the light-emitting parts includes multiple semiconductor layers including a first semiconductor layer, an active layer, and a second semiconductor layer, laminated in sequence, the first semiconductor layer having a first conductivity, the active layer generating light through the recombination of an electron and a hole, and the second semiconductor layer having a second conductivity different from the first conductivity; a non-conductive reflecting film which is formed to cover the multiple semiconductor layers and reflects light generated from the active layer; a first electrode which is provided to electrically communicate with the first semiconductor layer of the first light-emitting part and which supplies one of an electron and a hole; a second electrode which is provided to electrically communicate with the second semiconductor layer of the second light-emitting part and which supplies the other of the electron and the hole; and an auxiliary pad formed on the non-conductive reflecting film which covers the third light-emitting part.

Semiconductor light emitting element

A gallium nitride group compound semiconductor laser diode includes at least one pn junction layer disposed between an n-type layer and a p-type layer. The n-type layer is formed from a gallium nitride group compound semiconductor material defined by the composition equation (Alx Ga1-x)y In1-y N (where 0≦x≦1 and 0≦y≦1). The p-type layer, doped with an acceptor impurity, is obtained by electron beam irradiating a gallium nitride group compound semiconductor material defined by the composition equation (Alx' Ga1-x')y' In1-y' N (where 0≦x'≦1, 0≦y'≦1, x=x' or x≠x', and, y=y' or y≠y'). The improved gallium nitride group semiconductor laser diode of the present invention is found to emit light in the visible short wavelength spectrum of light which includes the blue, violet and ultraviolet regions.

Gallium nitride group compound semiconductor laser diode

Marked improvements in the crystal- line quality of GaN enabled the production of GaN-based p−n junction blue-light-emitting and violet-laser diodes. These robust, ener- getically efficient devices have opened up a new frontier in optoelectronics. A new arena of wide-bandgap semiconductors has been developed due to marked improvements in the crystalline quality of nitrides. In this article, we review breakthroughs in the crystal growth and conductivity control of nitride semicon- ductors during the development of p−n junc- tion blue-light-emitting devices. Recent prog- ress mainly based on the present authors' work and future prospects of nitride semicon- ductors are also discussed. Group III nitride semiconductors are recog- nized as one of the most promising materials for fabricating optical devices in the visible short-wavelength and UV region. To develop such novel devices and clarify the intrinsic materials properties of nitrides, it is essential to grow high-quality single crystals and control their electrical conductivity. However, high- quality epitaxial GaN was impossible to grow and its conductivity was uncontrollable. These problems have prevented the development of GaN-based p−n junction blue-light-emitting devices for many years. 1) In 1986, we achieved a marked improve- ment in the crystal quality of GaN which enabled us to realize p-type conduction in nitrides and to control the conductivity of n-type nitrides in 1989. In the same year, these achievements led to the invention of the world's first GaN p−n junction blue/UV-light- emitting diode (LED). In 1990, stimulated emis- sion in the UV region at room-temperature (RT), which is indispensable for laser action, was also achieved. These breakthroughs inspired nitride researchers around the world to exert great effort, which eventually led to the commercialization of high-performance blue LEDs and long-lifetime violet-laser diodes (LDs), and to the development of nitride-based devices such as UV detectors and high-speed field-effect transistors.

http://www.jsap.or.jp/jsapi/Pdf/Number16/04_JJAP-IRP.pdf

Breakthroughs in Improving Crystal Quality of GaN and Invention of the p−n Junction Blue-Light-Emitting Diode Breakthroughs in Improving Crystal Quality of GaN and Invention of the p−n Junction Blue-Light-Emitting Diode

Disclosed are a gallium nitride type semiconductor device that has a single crystal of (Ga 1-x Al x ) 1-y In y N, which suppresses the occurrence of crystal defects and thus has very high crystallization and considerably excellent flatness, and a method of fabricating the same. The gallium nitride type semiconductor device comprises a silicon substrate, an intermediate layer consisting of a compound containing at least aluminum and nitrogen and formed on the silicon substrate, and a crystal layer of (Ga 1-x Al x ) 1-y In y N (0≦x≧1, 0≦y≦1, excluding the case of x=1 and y=0). According to the method of fabricating a gallium nitride base semiconductor device, a silicon single crystal substrate is kept at a temperature of 400° to 1300° C. and is held in the atmosphere where a metaloganic compound containing at least aluminum and a nitrogen-containing compound are present to form a thin intermediate layer containing at least aluminum and nitrogen on a part or the entirety of the surface of the single crystal substrate, and then at least one layer or multiple layers of a single crystal of (Ga 1-x Al x ).sub. 1-y In y N are formed on the intermediate layer.

Method of fabricating a gallium nitride based semiconductor device with an aluminum and nitrogen containing intermediate layer

A process and apparatus, whereby in the process of vapor growth of a gallium nitride group semiconductor (Alx Ga1-x N; inclusive of x=0) thin film using an organometallic compound gas, a reactant gas which grows Alx Ga1-x N and a reactant gas containing a doping element are separately introduced near to a susceptor and mixed in the vicinity of a substrate held by the susceptor to grow an I-type Alx Ga1-x N thin film, are disclosed. Also, a process of vapor growth and apparatus having a mixing tube and a process and apparatus for inclining the susceptor relative to the reactant gas flow are disclosed. Moreover, a process and apparatus, whereby the Alx Ga1-x N thin film is subjected to the crystal growth using a plasma of the reactant gas under reduced pressure, under the irradiation of ultraviolet rays or laser beams, are disclosed.

Hiroshi Amano

Papers

Semiconductor light emitting element

Gallium nitride group compound semiconductor laser diode

Breakthroughs in Improving Crystal Quality of GaN and Invention of the p−n Junction Blue-Light-Emitting Diode Breakthroughs in Improving Crystal Quality of GaN and Invention of the p−n Junction Blue-Light-Emitting Diode

Method of fabricating a gallium nitride based semiconductor device with an aluminum and nitrogen containing intermediate layer

Process of vapor growth of gallium nitride and its apparatus