Sony Corporation

Shinichi Wada

Mitsuhiro Nakamura

Hideki Watanabe

Masaru Kuramoto

Tsutomu Imoto

Shigeru Kanematsu

Katsuhiko Takeuchi

Hidetoshi Kawasaki

Ichiro Hase

Masashi Yanagita

A transistor including a carrier transit layer that includes a compound semiconductor and a carrier supply layer in contact with the carrier transit layer. The carrier supply layer includes a compound semiconductor of a different type from the carrier transit layer. The transistor includes a gate electrode provided on the carrier supply layer, and a source electrode and a drain electrode provided on another surface of the carrier transit layer that is opposite to one surface on which the carrier supply layer is provided.

Transistor, semiconductor device, electronic apparatus, and method for producing transistor

A semiconductor laser element includes a stacked structure body, a second electrode, and a first electrode; a ridge stripe structureformed of at least part of the stacked structure body is formed; a side structure bodyformed of the stacked structure body is formed on both sides of the ridge stripe structure; the second electrodeis separated into a first portion for sending a direct current to the first electrode via a light emitting region and a second portionB for applying an electric field to a saturable absorption region; a protection electrodeis formed on a portion adjacent to the second portionB of the second electrode of at least one side structure body; and an insulating layermade of an oxide insulating material is formed to extend from on a portion of the ridge stripe structureto on a portion of the side structure body, on which portions neither the second electrode nor the protection electrodeis formed.

Semiconductor laser element

A high-accuracy, threshold-voltage-settable, field-effect transistor and a semiconductor device including the field-effect transistor are provided. The field-effect transistor, having a channel layer through which carriers move between a source and a drain, includes a doped layer for adjusting the threshold voltage of the transistor by changing the carrier concentration in the channel layer. In particular, the doped layer is provided in a semiconductor substrate by implantation of impurities.

Field-effect transistor, semiconductor device including field-effect transistor, and method for manufacturing field-effect transistor and semiconductor device

There is provided a protection circuit of a field effect transistor having a structure which can be fabricated without restricting a pattern layout and without increasing a process step. A protection circuit of a field effect transistor is a protection circuit of a Schottky gate HFET, and is a circuit in which a forward direction diode and a reverse direction diode are cascade-connected to form a diode unit and two such diode units are connected in series, and a gate line connected to a gate electrode of the HFET is grounded through the protection circuit. The diodes are diodes formed integrally with the Schottky gate HFET which is protected against surge breakdown, and are constituted as Schottky barrier diodes made of an n -GaAs cap layer formed on a GaAs substrate and Schottky electrodes formed on the n -GaAs cap layer.

Protection circuit of field effect transistor and semiconductor device

A semiconductor device operable with a single positive power source, enabling an increase in efficiency, and improved in high-frequency characteristics by lowering the resistivity of a gate contact, including a carrier run layer formed on a substrate for running of carriers; a carrier supply layer formed on the carrier run layer, having a larger bandgap than the carrier run layer, and containing a first conductivity type impurity; a barrier layer formed on the carrier supply layer and having a smaller bandgap than the carrier supply layer; a source electrode and a drain electrode formed on the barrier layer at a predetermined distance from each other; a gate electrode formed on the barrier layer between the source electrode and the drain electrode away from the source electrode and the drain electrode; and a first low resistivity region formed at least below the gate electrode in the barrier layer and containing a second conductivity type impurity opposite in conductivity to the first conductivity type, and a process of production of the same.

Semiconductor device and process of production of same

A semiconductor device that is easily operated with a single positive voltage supply and exhibits an excellent linearity of mutual conductance and source-gate capacitance with regard to a gate voltage is provided. The semiconductor device comprises a second barrier layer of AlGaAs, a channel layer of InGaAs and a first barrier layer of AlGaAs that are stacked in this order on a substrate of GaAs with a buffer layer of u-GaAs between the substrate and the second barrier layer. Carrier supply regions doped with n-type impurity are formed in part of the first and second barrier layers. A low resistivity region including a high concentration of p-type impurity (Zn) is formed in the first barrier layer. The low resistivity region is buried in a high resistivity region and brought to contact with a gate electrode. Upon an application of positive voltage to the gate electrode, a carrier deficient region disappears in the channel layer and no parasitic resistance component remains.

Semiconductor device

An electrode having a good contact between a semiconductor substrate and an electrode film is formed in a semiconductor device, and a manufacturing method therefor. On first AlGaAs of a compound semiconductor substrate, a second semiconductor layer of second AlGaAs formed with p-type impurity region is formed, a third semiconductor layer of low resistance GaAs and AlGaAs having a band gap narrower than that of the second semiconductor layer is formed thereon and, further, an electrode film is formed on the third semiconductor layer.

Ohmic contact improvement between layer of a semiconductor device

A semiconductor device including field effect transistors having different threshold voltages formed on a common base, characterized by including: a first field effect transistor having a p-n junction gate; and a second field effect transistor having a Schottky junction gate; wherein a threshold voltage of the first field effect transistor is set on the basis of a depth of the p-n junction, and a threshold voltage of the second field effect transistor is set on the basis of selection of a barrier potential of the Schottky junction.

Growing community of inventors

Kanagawa, Japan

Shinichi Wada