Hitachi, Ltd.

Hitachi Haramachi Semi-conductor, Ltd.

Hitachi Haramichi Electronics Co., Ltd.

Hidetoshi Arakawa

Mutsuhiro Mori

Naoki Sakurai

Yasumiti Yasuda

Hiroshi Owada

Hideki Miyazaki

Akihiko Kanouda

Kenichi Onda

Yoshitaka Sugawara

Masamitsu Inaba

A semiconductor device includes an emitter region, a collector region provided directly under the emitter region, and a two-region base structure. The first base region is interposed between the emitter and collector regions, and the second base region supports the collector region. The aforementioned regions have a progressively higher impurity concentrations, with the collector region having an impurity concentration higher than that of the first base region, the second base region having an impurity concentration higher than that of the collector region, and the emitter region having an impurity concentration higher than that of the base region. Also included is a resistance region formed, in one embodiment, from a projecting end portion of one of the base layers. The projecting end portion of the base is fabricated so that both base portions contact one another in the resistance region, and consequently both base portions are of the same potential. Electrodes are also provided for ohmicly contacting the emitter, collector, and base regions. The two-region base structure enables the device to achieve a high resistance, and thus to achieve simultaneously a high breakdown voltage and a high frequency (speed) characteristic.

Semiconductor device

A semiconductor integrated circuit unit, suitable for the control of a motor, has an integrated structure within the same semiconductor substrate, comprising an inverter circuit, drive circuits for driving the switching elements of the inverter circuit, an internal power source circuit for supplying power to the drive circuits which drive the upper arm side of the inverter circuit, and a logical circuit for transmitting a signal to the drive circuits which drive the upper arm side of the inverter circuit.

Semiconductor integrated circuit unit

A semiconductor device includes a diode having a Schottky barrier and a MOS transistor integrally formed in one and the same semiconductor substrate in which the diode and MOS transistor have their main electrode in common use. The diode has a first diode portion having a pn junction in a current-passing direction and a second diode portion having a combination of the Schottky barrier and another pn junction in the current passing direction.

Composite semiconductor device with Schottky and pn junctions

A semiconductor device is provided wherein a first diode having a pn junction and a second diode having a combination of a Schottky barrier and a pn junction in a current-passing direction are provided side by side in a direction perpendicular to the current-passing direction. When a forward current with a current density J.sub.F is passed into the second diode, the relation ##EQU1## is established in a forward voltage V.sub.F range of 0.1 (V) to 0.3 (V), where k represents the Boltzmann constant (.apprxeq.1.38.times.10.sup.-23 J/K), T represents the absolute temperature, and q represents the quantity of electron charges (.apprxeq.1.6.times.10.sup.-19 C). The first diode can have a first semiconductor region of one conductivity type and a second semiconductor region of the other conductivity type adjacent to the first semiconductor region to form a pn junction therebetween, so as to be in ohmic contact with one main electrode, and so as to have an impurity concentration higher than that of the first semiconductor region. The second diode can be formed by the first semiconductor region of the one conductivity type and a third semiconductor region of the other conductivity type analogously as above.

Semiconductor Schottky barrier device with pn junctions

A semiconductor device has a first diode having a pn junction and a second diode having a combination of a Schottky barrier and a pn junction in a current-passing direction provided side by side in a direction perpendicular to the current-passing direction. When a forward current with a current density J.sub.F is passed into the second diodes, the relation ##EQU1## is established in a forward voltage V.sub.F range of 0.1 (V) to 0.3 (V), where k represents the Boltzmann constant, T represents the absolute temperature, and q represents the quantity of electron charges. The first diode is constituted by a first semiconductor region of one conductive type and a second semiconductor region of the other conductive type provided so as to be adjacent to the first semiconductor region to form a pn junction, so as to be in ohmic contact with one main electrode, and so as to have an impurity concentration higher than that of the first semiconductor region, and the second diode is constituted by the first semiconductor region of the one conductive type and a third semiconductor region of the other conductive type provided so as to be adjacent to the first semiconductor region to form a pn junction, so as to be in contact through a Schottky barrier with the one main electrode, and so as to have an impurity concentration higher than the first semiconductor region.

Growing community of inventors

Kitaibaraki, Japan

Hidetoshi Arakawa