Matsushita Electric Industrial Co., Ltd.

Koichi Mizuno

Kentaro Setsune

Hidetaka Higashino

Akira Enokihara

Hideaki Adachi

Nobuyuki Otsuka

Shigeo Yoshii

Asamira Suzuki

Yo Ichikawa

Toshiya Yokogawa

Kiyotaka Wasa

Shigemi Kohiki

Shinichiro Hatta

Toshifumi Sato

Tomoaki Matsushima

A ballistic semiconductor device of the present invention comprises a n-type emitter layer (), a base layer () made of n-type InGaN, a n-type collector layer (), an emitter barrier layer () interposed between the emitter layer () and the base layer () and having a band gap larger than that of the base layer (), and a collector barrier layer () interposed between the base layer () and the collector layer () and having a band gap larger than that of the base layer (), and operates at 10 GHz or higher.

Ballistic semiconductor device

The present invention relates to a semiconductor device having a multi-layered structure comprising an emitter layer, a base layer, and a collector layer, each composed of a group III-V n-type compound semiconductor in this order; a quantum dot barrier layer disposed between the emitter layer and the base layer; a collector electrode, a base electrode and the emitter layer all connected to an emitter electrode; the quantum dot barrier layer having a plurality of quantum dots being sandwiched between first and second barrier layers from the emitter layer side and the base layer side, respectively and each having a portion that is convex to the base layer; a base layer side interface in the second barrier layer, and collector layer side and emitter layer side interfaces in the base layer having curvatures that are convex to the collector layer corresponding to the convex portions of the quantum dots.

Semiconductor device

The present invention provides a switching device comprising first to third connection terminals, a first FET provided with a pair of terminals one of which is connected, via a first direct-current blocking capacitive element, to the first connection terminal and the other of which is connected, via another first direct-current blocking capacitive element, to the second connection terminal, and a second FET provided with a pair of terminals one of which is connected, via a second direct-current blocking capacitive element, to the first connection terminal and the other of which is connected, via another second direct-current blocking capacitive element, to the third connection terminal. The channel type of the first FET is the same as the channel type of the second FET. A first bias voltage is applied to a gate of the first FET, and a second bias voltage is applied to both the main terminals of the second FET. In addition, either a voltage having a first given value or a voltage having a second given value is applied, as a first control value, to both the main terminals of the first FET and to a gate of the second FET, thereby establishing switching between a first connection state of electrically connecting the first connection terminal and the second connection terminal with each other and a second connection state of electrically connecting the first connection terminal and the third connection terminal with each other.

Switching device

A plasma oscillation switching device of the present invention comprises semiconductor substrate; first barrier layerthat is composed of a III-V compound semiconductor and formed on the substrate; channel layerthat is composed of a III-V compound semiconductor and formed on the first barrier layer; second barrier layerthat is composed of a III-V compound semiconductor and formed on the channel layer; source electrode, gate electrodeand drain electrodeprovided on the second barrier layer, wherein the first barrier layer includes n-type diffusion layer, the second barrier layer includes p-type diffusion layer, the band gap of the channel layer is smaller than the band gaps of the first and the second barrier layers, two-dimensional electron gas EG is accumulated at the conduction band at the boundary between the first barrier layer and the channel layer, two-dimensional hole gas HG is accumulated at the valence band at the boundary between the second barrier layer and the channel layer, and these electrodes are formed on the barrier layer through the insulating layer

Plasma oscillation switching device

A hetero field effect transistor according to the present invention comprises an InP substrate, a channel layer provided on the InP substrate with a buffer layer disposed between the InP substrate and the channel layer, a spacer layer constituted by a semiconductor having a band gap larger than that of the channel layer formed to hetero-join to the channel layer, and a carrier supply layer formed to be adjacent to the spacer layer, wherein the channel layer comprises a predetermined semiconductor layer constituted by a compound semiconductor represented by a formula GaInNAin which A is As or Sb, composition x satisfies 0&#x2266;x&#x2266;0.2, and composition y satisfies 0.03&#x2266;y&#x2266;0.10.

Gallium indium nitride arsenide based epitaxial wafer, a hetero field effect transistor using the wafer, and a method of fabricating the hetero field effect transistor

In a small transmission line type high-frequency circuit element that has small loss due to conductor resistance and has a high Q value, an error in the dimension of a pattern, etc. can be corrected to adjust element characteristics. An elliptical shape resonator ( ) that is formed of an electric conductor is formed on a substrate ( ), while a pair of input-output terminals ( ) are formed on a substrate ( ). Substrate ( ) on which resonator ( ) is formed and substrate ( ) on which input-output terminal ( ) is formed are located parallel to each other, with a surface on which resonator ( ) is formed and a surface on which input-output terminal ( ) is formed being opposed. Substrates ( ) and ( ) that are located parallel to each other are relatively moved by a mechanical mechanism that uses a screw and moves slightly. Also, substrate ( ) is rotated by the mechanical mechanism that uses a screw and moves slightly around the center axis of resonator ( ) as a rotation axis ( ).

High-frequency circuit element having a superconductive resonator tuned by another movable resonator

High-frequency circuit element having a superconductive resonator with an electroconductive film about the periphery

High-frequency circuit element in which a resonator and input/ouputs are

A field-effect type superconducting device includes a channel layer. The channel layer includes Bi-based oxide compound containing Cu. A source electrode contacts the channel layer. A drain electrode contacts the channel layer. A gate insulating film made of insulating material extends on on the channel layer. A gate electrode extends on the gate insulating film.

Field-effect type superconducting device including bi-base oxide

An effective high frequency oscillator is made of a plurality of Josephson devices. A high frequency converter as a high frequency circuit is made of the high frequency oscillator, nonlinear superconductor devices, and transmission line. Josephson devices are connected in parallel to make a superconductor module. Then superconductive modules are connected in series for high frequency via a phase locking circuit such as a thin film type capacitor to make the high frequency oscillator. Consequently, the high frequency oscillator is used as a local oscillator for a frequency converter. The high frequency system comprises a high frequency package housing a high frequency circuit, a cooling unit including a low temperature stage in thermal contact with the high frequency package, and a shielding case for housing the high frequency circuit and the low temperature stage. The high frequency system of the present invention provides a small-sized and power-saving high frequency circuit having operational stability.

High frequency system including a superconductive device and temperature

A superconductor device is provided including a base, a base electrode formed on the base which is made of a Bi-system oxide superconductive material containing an alkaline earth metal, a barrier layer formed on the base electrode which is made of Bi--Sr--Cu--O, a counter electrode formed on the barrier layer which is made of a Bi-system oxide superconductive material containing an alkaline earth metal, a contact electrode formed so as contact with the counter electrode, and a separation layer for separating said contact electrode from said base electrode.

Bi-Sr-Ca-Cu-O superconductor junction through a Bi-Sr-Cu-O barrier layer

A superconducting element includes a superconducting thin film bridge extending along the surface of a substrate, and a control electrode member for injecting quasi particles into a portion of an intersection region of the superconducting thin film bridge. The intersection region extends across the superconducting thin film bridge in a direction which is perpendicular to the current flow direction of the superconducting thin film bridge. A remaining portion of the intersection region, which is not injected with quasi particles by the control electrode member, operates as a weak-coupling bridge to thereby control the current flow within the superconducting thin film bridge.

Superconducting weak-link bridge

A method of fabricating a thin-film Hg-containing oxide superconductor is disclosed, which comprises forming a thin film on a substrate, said thin film containing mercury, an alkaline earth element, and copper as main components thereof; and subjecting said substrate with the thin film to a heat treatment in an oxygen-containing atmosphere at an oxygen partial pressure of 1/500 to 1/10 atm, to convert said thin film to the thin-film superconductor.

Method of forming Hg-containing oxide superconducting films

A thin-film superconductor includes a substrate, a ferroelectric film, and a superconducting oxide film. The ferroelectric film extends on the substrate. The ferroelectric film is made of a crystal contains Bi and O. The superconducting oxide film extends on the ferroelectric film, and containing Bi, Cu, and an alkaline-earth metal element. The superconducting oxide film may contain at least two different alkaline-earth metal elements.

Thin-film high Tc superconductor comprising a ferroelectric buffer layer

A Josephson device, comprising a junction formed by forming the first layer-shaped oxide superconductor thin film including a plurality of Cu-O layers on a substrate, a barrier layer thereon and the second layer-shaped oxide superconductor thin film on the barrier layer. The Josephson device according to the present invention is manufactured by forming the first layer-shaped oxide superconductor thin film on a substrate, forming a barrier layer in the same vacuum chamber, defining patterns to said barrier layer and said first layer-shaped oxide superconductor thin film, forming an interlayer insulating film on said barrier layer, removing said interlayer insulating film in a region serving as a junction, effecting exposure to oxygen plasma, forming the second layer-shaped oxide superconductor thin film in contact with a part of the surface of said barrier layer and defining patterns to said second layer-shaped oxide superconductor thin film.

Growing community of inventors

Nara, Japan

Koichi Mizuno