Hitachi, Ltd.

Hitachi Vlsi Engineering Corp.

Hitachi, Ltd. Hitachi Cabel

Kenji Hiruma

Tadashi Fukuzawa

Hiroyoshi Matsumura

Shigeo Goto

Hitoshi Nakamura

Hidetoshi Matsumoto

Toshiyuki Usagawa

Masahiko Kawata

Masamitsu Yazawa

Susumu Takahashi

Tomonori Tanoue

Kensuke Ogawa

Yoshinori Imamura

Shinji Tsuji

Koji Ishida

Toshio Katsuyama

Masao Yamane

Hiroshi Kakibayashi

Katsuhiko Mitani

Hiroyoshi Matumura

Eizaburo Yamada

Gerard P Morgan

Toshiaki Tanaka

Yasunari Umemoto

Naoki Chinone

Toshiaki Masuhara

Yoshihisa Fujisaki

Yasuhiro Shiraki

Hiroaki Inoue

Shinichiro Takatani

Ken Yamaguchi

Masanari Koguchi

Tomoyoshi Mishima

Takao Kuroda

Akihito Hongo

Makoto Morioka

Yoshifumi Katayama

Kazuyuki Nagatsuma

Motohisa Hirao

Yasutoshi Kashiwada

Yoko Uchida

Nobutaka Futigami

Keiichi Haraguchi

Masamits Yazawa

Hiroshi Hamada

Akio Oishi

Semiconductor light emitting device

A semiconductor device (e.g., hetero-junction field-effect transistor) which has decreased capacitance between the gate and drain, and which has decreased source resistance, is provided. Structure in which a contact layer 6 comes in contact with the side surfaces of a channel layer 3 but does not come in contact with the side surfaces of a barrier layer 4 enables capacitance between the gate and drain to be decreased. This capacitance can be decreased down to 1.5 pF per 10 .mu.m of the width.

Semiconductor device having first and second stacked semiconductor

This invention discloses a heterojunction type field effect transistor such as 2DEG-FET and a heterojunction type bipolar transistor such as 2DEG-HBT. The former is fabricated by applying to the formation of its source and drain regions a technique which causes the disorder of the heterojunction by intoduction of an impurity such as by ion implantation or a technique which causes the disorder of the heterojunction by forming a film made of at least one kind of material selected from insulators, metals and semiconductors which have a different linear coefficient of thermal expansion from that of the material of a semiconductor substrate on the heterojunction semiconductor region which is to be disordered. The latter is fabricated by applying either of the techniques described above to a base ohmic contact region. These semiconductor devices can reduce the source-gate resistance and the parasitic base resistance. The invention discloses also the structure of the ohmic contact layer which has a trench on the surface thereof and is particularly effective for reducing the source-gate parasitic resistance.

Semiconductor device having a heterojunction and a two dimensional gas

A field effect transistor and a ballistic transistor using semiconductor whiskers each having a desired diameter and formed at s desired location, a semiconductor vacuum microelectronic device using the same as electron emitting materials, a light emitting device using the same as quantum wires and the like are disclosed.

Semiconductor device using whiskers

A field-effect transistor or a bipolar transistor may be provided in which the contact resistance between a channel layer or base layer and a contact layer are reduced. For example, an InGaAs buffer layer may be formed on the substrate side of an InGaAs channel layer of a field-effect transistor and by the bypassing effect that carriers pass through this InGaAs buffer layer, the InGaAs channel layer comes in contact with the contact layer with a low resistance. The contact resistance between the InGaAs channel layer and the contact layer can be reduced to 10 ohm per a width of 10.mu.m, and as a result, the value of transconductance factor K of a field-effect transistor can be increased in 14 mA/V.sup.2 per a width of 10.mu.m.

Semiconductor device having reduced contact resistance between a channel

A semiconductor light-emitting device includes a plurality of semiconductor rods, each of which has a pn junction. The semiconductor rods are formed on a semiconductor substrate such that the plurality of semiconductor rods are arranged at a distance substantially equal to an integer multiple of the wavelength of light emitted from the semiconductor rod. With such devices, various novel optical devices such as a micro-cavity laser of which the threshold current is extremely small and a coherent light-emitting device having no threshold value can be realized.

Semiconductor optical device with nanowhiskers

This invention discloses a heterojunction type field effect transistor such as 2DEG-FET and a heterojunction type bipolar transistor such as 2DEG-HBT. The former is fabricated by applying to the formation of its source and drain regions a technique which causes the disorder of the heterojunction by introduction of an impurity such as by ion implantation or a technique which causes the disorder of the heterojunction by forming a film made of at least one kind of material selected from insulators, metals and semiconductors which have a different linear coefficient of thermal expansion from that of the material of a semiconductor substrate on the heterojunction semiconductor region which is to be disordered. The latter is fabricated by applying either of the techniques described above to a base ohmic contact region. These semiconductor devices can reduce the source-gate resistance and the parasitic base resistance. The invention discloses also the structure of the ohmic contact layer which has a trench on the surface thereof and is particularly effective for reducing the source-gate parasitic resistance.

Semiconductor device having a two-dimensional electron gas as an active

A solid film forming apparatus, e.g., an MO-MBE (Metal-Organic Molecular Beam Epitaxy) apparatus, wherein evacuatable containers isolated from a growth chamber by a switching device and connected to raw material gas introduction pipings are provided between the growth chamber for a solid film, e.g., a compound semiconductor, and raw material gas introduction pipings. Growth of the solid film is controlled by opening and closing the switching device and evacuating the container at least while the switching device is closed during the growth of the solid film. An undesired influence on the growing film due to residual gas in the containers which are not used for growth can be prevented and, hence, interception and introduction of the raw material gas into the growth chamber can be performed with remarkably high controllability, and films of superior abruptness of the interface between films, e.g., the heterojunction of the compound semiconductor, can be obtained.

Solid film growth apparatus

A semiconductor optical device in which a hetero-structure is constructed by sandwiching a semiconductor layer including a thin film made of a semiconductor or insulator between semiconductors having a larger band gap than that of the thin film so that the electron-hole pairs generated through the thin film may recombine by the tunnel effect to emit an optical beam. The optical device is equipped with electrodes for controlling the probability of said recombination.

Semiconductor optical device

An optical modulator which utilizes the Stark effect according to which the absorption spectra change if an electric field is applied to the excitons. A thin film of a suitable thickness composed of a semiconductor and an insulator or composed of either one of them, is formed between a group of electrons and a group of positive holes that constitute excitons, so that the excitons are stabilized. The optical modulator performs the modulation at high speeds maintaining a high efficiency.

Optical modulator

An epitaxial crystal grown layer structure which permits, on an In-doped GaAs substrate, which will be industrially used in large quantities, the growth of an epitaxial layer having the same good quality as the epitaxial layer grown on an undoped GaAs substrate.

Semiconductor device having strained superlattice buffer layers with

The present invention provides a waveguide type optical switch which has a high extinction ratio and can be driven efficiently at a low voltage or a low current injection. Where the waveguide type optical switch is used as a reflection type optical switch, the switch section is of current confinement structure, and where it is used as a directional coupler type optical switch, the pn junction is formed in the position where the optical electric field takes the maximum value for the fundamental mode of the light propagating in the waveguide.

Waveguide optical switches

A distributed feedback semiconductor laser provided with a grating which effects optical feedback by means of periodic corrugation disposed inside an optical resonator. The optical resonator has at least two regions having different Bragg wavelengths, and these regions are arranged longitudinally in the direction of an optical axis. The laser device can realize stable single longitudinal mode oscillation through variation of the refractive indexes of the regions nonuniformly around an average value.

Distributed-feedback semiconductor laser device

When a semiconductor device is produced by growing epitaxially a compound semiconductor layer on a Si or Ge substrate, lattice matching between the substrate crystal and the compound semiconductor layer to be formed on the substrate can be improved by ion-implanting an ion species element, which increases the lattice constant of Si or Ge as the substrate, into the Si or Ge substrate in order to increase its lattice constant. In comparison with conventional semiconductor devices using Si or Ge into which ion implantation is not made, the semiconductor device produced by the method described above can improve remarkably its characteristics. In the case of a semiconductor laser device, for example, its threshold value drops drastically and its service life can be prolonged remarkably.

Method of growing heteroepitaxial InP on Si using Sn substrate

An optical waveguide comprising a layer formed on a substrate, having a mixed composition of silicon oxide and silicon nitride and having an arbitrary value of refractive index ranging between those of the silicon oxide and the silicon nitride. The layer of said mixed composition can be formed on the substrate to easily fabricate the optical waveguide of the present invention by conducting a sputtering method employing a Si target and controlling the composition of a sputtering gas composed of a mixture of N.sub.2 and O.sub.2 gases.

Optical waveguide having a silicon oxi-nitride layer

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Koganei, Japan

Kenji Hiruma