Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Shinichi Sonetaka

Yasuyuki Toyoda

Yorito Ota

Kazuhiro Arai

Masahiko Inamori

Hiroaki Kawano

Junji Kaido

A semiconductor device and a radio frequency circuit which are appropriate for multiband, multimode performance can be realized as a semiconductor device including a field-effect transistor formed on a semiconductor substrate, and include: ohmic electrodes serving as source and drain electrodes of the field-effect transistor, first and second Schottky electrodes provided between the ohmic electrodes and serving as gate electrodes of the field-effect transistor, and a third Schottky electrode provided and grounded between the first and second Schottky electrodes.

Semiconductor device, radio frequency circuit, and radio frequency power amplifier

A semiconductor device includes a semiconductor substrate of a first conductive type, a collector layer formed on the semiconductor substrate and made of a first semiconductor being of the first conductive type and having a higher resistance than that of the semiconductor substrate, an intrinsic base region having a junction surface with the collector layer and made of a second semiconductor of a second conductive type, and an emitter region having a junction surface with the intrinsic base region and made of a third semiconductor of the first conductive type. A periphery of the intrinsic base region is surrounded by an insulating region extending from the collector layer to the semiconductor substrate.

Semiconductor device and method for fabricating the same

There is provided a bipolar transistor that enables a desirably enhanced high-frequency performance to be obtained when used as an oscillation amplifier of an oscillation circuit, and that is miniaturized and reduced in cost. A capacitance adjustment line () connected to a base pad () forms a parasitic capacitor with respect to an Ncollector substrate by interposing an insulating film () and an N collector substrate therebetween, thereby increasing collector-base capacitance C. This capacitor is incorporated into a bipolar transistor, which functions as an oscillation amplifier and has a small transistor operation region (), at least as a part of a balance capacitor constituting the oscillation circuit in the course of production of a semiconductor.

Bipolar transistor, oscillation circuit, and voltage controlled oscillator

Bipolar transistor, for voltage controlled oscillator using a capacitance adjustment line

A bipolar transistor includes the first group of transistors, the second group of transistors, the third group of transistorsand the fourth group of transistors. The groups of transistors have unit transistors with emitters, bases and collectors that are connected electrically in parallel and the number of unit transistors is different from group to group and 2, 4, 8, and 16, respectively.

Growing community of inventors

Ibaraki, Japan

Shinichi Sonetaka