Rohm Co., Ltd.

Kyoto University

Hokkaido University

Takui Sakaguchi

Yuki Nakano

Masatoshi Aketa

Dai Ohnishi

Eiji Miyai

Hiroaki Misawa

Yoichi Mugino

Yoshikatsu Miura

Wataru Kunishi

Kosei Ueno

Susumu Noda

Seita Iwahashi

Kazuya Nagase

Seigo Mori

Dai Onishi

Minoru Nakagawa

Toshiyuki Nobuoka

Yuichiro Nanen

A semiconductor device includes a semiconductor layer having a first surface and a second surface, a unit cell including a diode region of a first conductivity type formed in a surface layer portion of the first surface of the semiconductor layer, a well region of a second conductivity type formed in the surface layer portion of the first surface of the semiconductor layer along a peripheral edge of the diode region, and a first conductivity type region formed in a surface layer portion of the well region, a gate electrode layer facing the well region and the first conductivity type region through a gate insulating layer and a first surface electrode covering the diode region and the first conductivity type region on the first surface of the semiconductor layer, and forming a Schottky junction with the diode region and an ohmic junction with the first conductivity type region.

Semiconductor device having a gate insulating layer

An SiC semiconductor device includes an SiC semiconductor layer having a first main surface and a second main surface, a gate electrode embedded in a trench with a gate insulating layer, a source region of a first conductivity type formed in a side of the trench in a surface laver portion of the first main surface, a body region of a second conductivity type formed in a region at the second main surface side with respect to the source region in the surface layer portion of the first main surface, a drift region of the first conductivity type formed in a region at the second main surface side in the SiC semiconductor layer, and a contact region of the second conductivity type having an impurity concentration of not more than 1.0×10cmand formed in the surface layer portion of the first main surface.

SiC semiconductor device

A semiconductor device includes a semiconductor layer having a first main surface on one side and a second main surface on the other side, a unit cell including a diode region of a first conductivity type formed in a surface layer portion of the first main surface of the semiconductor layer, a well region of a second conductivity type formed in the surface layer portion of the first main surface of the semiconductor layer along a peripheral edge of the diode region, and a first conductivity type region formed in a surface layer portion of the well region, a gate electrode layer facing the well region and the first conductivity type region through a gate insulating layer and a first main surface electrode covering the diode region and the first conductivity type region on the first main surface of the semiconductor layer, and forming a Schottky junction with the diode region and an ohmic junction with the first conductivity type region.

Semiconductor device

A semiconductor deviceincludes a trench gate structureformed in a surface layer portion of a first principal surface of a semiconductor layer. A source regionand a well regionare formed in a surface layer portion of the first principal surface of the semiconductor layer at a side of the trench gate structure. The well regionis formed in a region at a side of the second principal surface of the semiconductor layer with respect to the source region. A channel is formed along the trench gate structurein a portion of the well region. A multilayer regionis formed in a region between the trench gate structureand the source regionin the semiconductor layer. The multilayer regionhas a p type impurity regionformed in the surface layer portion of the first principal surface of the semiconductor layer and an n type impurity regionformed in a side of the second principal surface of the semiconductor layer with respect to the second conductivity type impurity region

The 2D-PC surface emitting laser includes: a PC layer; and a lattice point for forming resonant-state arranged in the photonic crystal layer, and configured so that a light wave in a band edge in photonic band structure in the PC layer is diffracted in a plane of the PC layer, and is diffracted in a surface vertical direction of the PC layer. The perturbation for diffracting the light wave in the surface vertical direction of the PC layer is applied to the lattice point for forming resonant-state. The term 'perturbation' means that modulation is periodically applied to the lattice point for forming resonant-state. For example, the periodic modulation may be refractive index modulation, hole-diameter modulation, or hole-depth modulation.

Two dimensional photonic crystal vertical cavity surface emitting lasers

A two-dimensional photonic crystal laser according to the present invention includes a two-dimensional photonic crystal layerhaving a base body made of AlGaAs (0&#x3c;&#x3b1;&#x3c;1) or (AlGa)InP (0&#x3c;=&#x3b2;&#x3c;1, 0&#x3c;&#x3b3;&#x3c;1) with modified refractive index areas (air holes)periodically arranged therein and an epitaxial growth layercreated on the two-dimensional photonic crystal layerby an epitaxial method. Since AlGaAs and (AlGa)InP are solid even at high temperatures, the air holeswill not be deformed in the process of creating the epitaxial growth layer, so that the performance of the two-dimensional photonic crystal layeras a resonator can be maintained at high levels.

Two-dimensional photonic crystal laser

A photonic crystal surface emission laser includes an active layer, and a photonic crystal layer made of a plate-shaped slab provided with modified refractive index area having a refractive index different from that of the slab, the modified refractive index areas being arranged on each of the lattice points of a first rhombic-like lattice and a second rhombic-like lattice in which both diagonals are mutually parallel and only one diagonal is of a different length, wherein a, a, a, and n satisfy the following inequality: 

Photonic crystal surface emission laser

In a metallic structure including a metallic nano-chain with plasmon resonance absorption, a metallic nanoparticle forming the metallic nano-chain is formed in a circular, triangle, or rhomboid shape. The wavelength selectivity can be increased also by forming a closed region by mutually linking all of metallic nanoparticles that are mutually linked with bottlenecks. In a photodetector, a photodetection unit including a current detection probe, a nano-chain unit, and a current detection probe is arranged on a substrate. The nano-chain unit is a metallic structure with plasmon resonance absorption, where metallic nanoparticles are mutually linked with bottlenecks. Each current detection probe has a corner whose tip is formed with a predetermined angle, and this corner is arranged to face the tip of the nano-chain unit, i.e., a corner of the metallic nanoparticle. Photodetection with high wavelength selectivity is performed based on a change in the initial voltage of the current-voltage characteristic.

Metallic structure and photodetector

Provided is a plasmon resonance detector that can detect temperature change in optical devices, in which the metal structure having plasmon resonance absorption is used for the optical devices. A diode formed of a conductive substrate, an n-type semiconductor layer, an i-type semiconductor layer, a p-type semiconductor layer, an n electrode (negative electrode), a p electrode (positive electrode), an insulating film, or the like is used as a semiconductor device whose resistance value changes in accordance with temperature change. A nanochain formed by connecting a plurality of metal nanoparticles is disposed on this diode. When the nanochain is irradiated with light, the nanochain generates heat. The heat generated in the nanochain is conducted to the diode. The resistance value of the diode changes in accordance with temperature change, and thus this change is read, a temperature or an amount of heat generation of the nanochain is measured, and existence and strength of the plasmon resonance are detected.

Growing community of inventors

Kyoto, Japan

Takui Sakaguchi