Sharp Kabushiki Kaisha Corporation

Shouichi Ohyama

Hiroshi Nakatsu

Takahisa Kurahashi

Tetsurou Murakami

Kazuaki Sasaki

Junichi Nakamura

Tetsuroh Murakami

Hiroyuki Hosoba

On a GaAs substrate (), are formed a DBR (Distributed Bragg Reflector) (), and a light-emitting layer () made of a plurality of layers of AlGaInP (0&#x2266;y&#x2266;1, 0&#x2266;z&#x2266;1) above the DBR (). A semiconductor layer or a plurality of semiconductor layers ()-() having a number of layers of 1 or more are formed on the light-emitting layer (), and a grating pattern for scattering light is formed on a surface of the semiconductor layer () by photolithography and by etching with a sulfuric acid/hydrogen peroxide based etchant. Thus, a semiconductor device small in radiation angle dependence of light emission wavelength, as well as a manufacturing method therefor, are provided.

Semiconductor light-emitting device and manufacturing method therefor

There is provided and manufactured, at a low cost and with high yields, a semiconductor light emitting device which allows extraction of light produced in an emitter layer not only from its top surface but also from its side surfaces and which has high luminance. An AlGaInP-based semiconductor light emitting device having a contact layermade of (AlGa)InP (0&#x2266;y&#x2266;1, 0&#x3c;z&#x3c;1) disposed between an emitter layerand a transparent substratewhich is transparent to emission wavelengths from the emitter layer

Semiconductor light emitting device and method for manufacturing same

A light emitting diode having, at least, an AlGaInP light emitting layer and a transparent electrode, wherein the transparent electrode is made of a ZnO film doped with a group III element or a compound thereof.

Light emitting diode

In a semiconductor light-emitting device, on an n-GaAs substrate are stacked an n-GaAs buffer layer, an n-cladding layer, an undoped active layer, a p-cladding layer, a p-intermediate band gap layer and a p-current diffusion layer. Further, a first electrode is formed under the n-GaAs substrate, and a second electrode is formed on the grown-layer side. In this process, a region of the p-intermediate band gap layer just under the second electrode is removed, the p-current diffusion layer is stacked in the removal region on the p-cladding layer, and a junction plane of the p-current diffusion layer and the p-cladding layer becomes high in resistance due to an energy band structure of type II. This semiconductor light-emitting device is capable of reducing ineffective currents with a simple construction and taking out light effectively to outside, thus enhancing the emission intensity.

Semiconductor light-emitting device and method for manufacturing thereof

A semiconductor light-emitting device includes an active layer having a single quantum well structure. The single quantum well structure enables a high-speed response such that the rise and fall time is 2.1 nsec. Further, the single quantum well active layer is doped with Zn at a concentration of 8&times;10 cm . Thereby, the half-value width of the light-emitting spectrum is 25 nm or more, which is wider than in the case of no doping. Thus, temperature dependence of an optical output is reduced.

Semiconductor light-emitting device

A resonant cavity type light emitting diode has a first DBR made of n-type AlAs or Al Ga As, a quantum well active layer, a second DBR made of p-type (Al Ga ) In P or Al In P, and an n-type current constriction layer on an n-type GaAs substrate. The first DBR and the second DBR form a resonator. The quantum well active layer is formed in a position of an antinode of a standing wave inside the resonator. Between the second DBR and the current constriction layer, there is provided a p-type GaP etching protection layer that has a value obtained by dividing resistivity by thickness being 1&times;10 &OHgr; or more. Since a current in a current flow pass formed in the current constriction layer hardly diffuses to the outside of the current flow pass, there is generated few region with low current density that causes deterioration of responsespeed in a quantum well layer. Thus, the light emitting diode has an excellent high-speed response.

Semiconductor light emitting device

In a semiconductor light-emitting element, a first DBR and a second DBR, with a specified spacing left between them, form a resonator, and a single quantum well active layer is positioned at the loop of a standing wave within this resonator. The single quantum well active layer is composed of a Ga In P well layer and a pair of (Al Ga ) In P barrier layers, which sandwiches the Ga In P well layer therebetween. The impurity concentration of the (Al Ga ) In P barrier layers is higher than that of the Ga In P well layer. For example, the impurity concentration of the Ga In P well layer is set to 2&times;10 cm , while the impurity concentration of the (Al Ga ) In P barrier layers is set to 2&times;10 cm .

Light emitting element with multiple multi-layer reflectors and a barrier layers

A light-emitting diode having an excellent high-speed response characteristic and capable of giving a large light output with a small variation of the light output during the operation is provided. In the light-emitting diode, an active layer comprising a single quantum well layer of p-type Ga In P, a lower barrier layer of p-type (Al Ga ) In P and an upper barrier layer of p-type (Al Ga ) In P is highly doped with p-type dopant (Zn, Mg, Be, C) or n-type dopant (Si, Se, Te) to produce non-radiative recombination level in the upper and lower barrier layers. Carriers injected into the quantum well layer not only recombine radiatively therein and also recombine nonradiatively at boundaries of the upper barrier layer and the lower barrier layer, remarkably increasing recombination velocity of carriers and dramatically improving the response characteristic.

Light-emitting semiconductor element

A light emitting diode comprising a multiple quantum well (MQW) layer as an active layer and a reflecting layer below the active layer, wherein the number and/or total thickness of well layers in the MQW layer is determined such that the MQW layer shows an external quantum efficiency higher than that of an MQW layer including a single well layer.

There is provided a semiconductor light emitting device having improved adhesion of an electrode by reducing defects in a crystal surface. An n-type AlGaInP lower clad layer , an AlGaInP active layer , a p-type AlGaInP upper clad layer , a p-type AlGaInP intermediate layer whose lattice matching rate &Dgr;a/a with GaAs is &minus;3.3%, a p-type AlGaInP current diffusion layer and a p-type electrode are laminated on an n-type GaAs substrate and an n-type electrode 18 is provided on the n-type GaAs substrate . Thus, the number of crystal defects in the crystal surface can be reduced to 20 or less per one LED by setting the value of the lattice matching rate &Dgr;a/a of the intermediate layer to be &minus;3.3%, which is lower than &minus;2.5%. As a result, adhesion of the p-type electrode formed on the current diffusion layer is improved and thereby the yield of LED can be enhanced.

Growing community of inventors

Ikoma-gun, Japan

Shouichi Ohyama