Sanken Electric Co., Ltd.

Hamamatsu-photonics K.k.

Tetsuji Matsuo

Mikio Tazima

Takashi Kato

Hidekazu Aoyagi

Junji Sato

Tokuaki Nihashi

Shunro Fuke

Masataka Yanagihara

Yoshiki Tada

Masahiro Sato

Shiro Takeda

Yoshihiro Ishigami

A semiconductor photocathode includes an AlGaN layer (0&#x2266;X&#x3c;1) bonded to a glass substrate via an SiOlayer and an alkali-metal-containing layer formed on the AlGaN layer. The AlGaN layer includes a first region, a second region, an intermediate region between the first and second regions. The second region has a semiconductor superlattice structure formed by laminating a barrier layer and a well layer alternately, the intermediate region has a semiconductor superlattice structure formed by laminating a barrier layer and a well layer alternately. When a pair of adjacent barrier and well layers is defined as a unit section, an average value of a composition ratio X of Al in a unit section decreases monotonously with distance from an interface position between the second region and the SiOlayer at least in the intermediate region.

Semiconductor photocathode and method for manufacturing the same

A semiconductor device includes a silicon substrate, an aluminum nitride layer which is arranged on the silicon substrate and has a region where silicon is doped thereof as an impurity, a buffer layer which is arranged on the aluminum nitride layer and has a structure where a plurality of nitride semiconductor films are laminated, and a semiconductor functional layer which is arranged on the buffer layer and made of nitride semiconductor.

Semiconductor device having nitride semiconductor layer

A semiconductor wafer includes a multilayered film having a structure in which nondoped first nitride semiconductor layers and nondoped second nitride semiconductor layers with a larger lattice constant than the first nitride semiconductor layer are laminated alternately, and a nondoped third nitride semiconductor layer which is located on the multilayered film and has a larger lattice constant than the first nitride semiconductor layer, wherein the semiconductor wafer has conductivity in a film-thickness direction.

Semiconductor wafer and semiconductor device having multilayered nitride semiconductor layer

A semiconductor light emitting device includes: a conductive substrate; a semiconductor light emitting layer which includes a first semiconductor layer formed on one surface of the conductive substrate and having a first conductivity type, and a second semiconductor layer formed on the first semiconductor layer and having a second conductivity type opposite to the first conductivity type; first light emitting spots which are alternately arranged around a periphery of the semiconductor light emitting layer and emitting light to an exterior from the semiconductor light emitting layer; second light emitting spots having surfaces intersecting with the first light emitting spots and emitting light at an amount smaller than an amount of light emitted via the first light emitting spots; and wirings arranged along the second light emitting spots and electrically short circuiting an area between the first light emitting layer and the surfaces of the conductive substrate.

Semiconductor light emitting device

A light-generating semiconductor region is grown on a substrate of electroconductive silicon or like light-absorptive material. An anode is placed atop the light-generating semiconductor region, and a cathode under the substrate. The light-generating semiconductor region and the substrate are encapsulated in an epoxy envelope. In order to prevent the substrate from absorbing the light that has been radiated from the light-generating semiconductor region and reflected back from the envelope, the substrate has its side surfaces covered by a reflector layer. The reflector layer has its surfaces roughened, as a result of the roughening of the underlying substrate surfaces by dicing, for scattering the incident light.

Light-emitting semiconductor device

An aspect of the present invention inheres in a semiconductor light-emitting element includes a light-emitting functional stacked body including a light-emitting region having a light-emitting function, and including a light extraction surface for extracting light emitted from the light-emitting region, and an upward convex lens disposed on the light extraction surface.

Semiconductor light-emitting element and semiconductor light-emitting element manufacturing method

The method is disclosed as applied to roughening the light-emitting surface of an LED wafer for reduction of the internal total reflection of the light generated. A masking film of silver is first deposited on the surface of a wafer to be diced into LED chips. Then the masking film is heated to cause its coagulation into discrete particles. Then, using the silver particles as a mask, the wafer surface is dry etched to create pits therein. The deposition of silver on the wafer surface and its thermal coagulation into particles may be either successive or concurrent.

Surface-roughening method

An LED has a light-generating semiconductor region formed on a baseplate via a metal-made reflector layer. The light-generating semiconductor region has an active layer sandwiched between a pair of claddings of opposite conductivity types. An annular marginal space is left around the reflector layer between the light-generating semiconductor region and the substrate. In order to preclude the thermal migration of the reflector metal onto the side surfaces of the light-generating semiconductor region, with a possible short-circuiting of the pair of claddings across the active layer, an anti-migration seal is received in the annular marginal space created around the reflector layer between the light-generating semiconductor region and the baseplate.

Light-emitting semiconductor device protected against reflector metal migration

An LED includes a light-generating semiconductor region having an active layer sandwiched between two confining layers of opposite conductivity types for generating light. A cathode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. A reflector of electroconductive material is formed on the other major surface of the semiconductor region for reflecting the light back toward the light-emitting surface of the semiconductor region. For protecting the LED against breakdown from overvoltages, a zener diode is employed which takes the form of a baseplate having two semiconductor regions of opposite conductivity types sandwiched between a pair of electrodes in the form of metal layers. The protector baseplate is integrated with the light-generating semiconductor region by joining one of the metal layers to the reflector under heat and pressure, thus serving as both mechanical support and overvoltage protector for the LED.

Light-emitting semiconductor device having an overvoltage protector

An LED includes a semiconductor region having an active layer sandwiched between two confining layers of opposite conductivity types for generating heat. A cathode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. Attached to the other major surface of the semiconductor region, via an ohmic contact layer, is a reflective metal layer for reflecting the light that has traversed the ohmic contact layer, back toward the semiconductor region. A transparent antidiffusion layer is interposed between the ohmic contact layer and the reflective layer in order to prevent the ohmic contact layer and the reflective layer from thermally diffusing from one into the other to the impairment of the reflectivity of the reflective layer.

Growing community of inventors

Niiza, Japan

Tetsuji Matsuo