Rohm Co., Ltd.

Hirotaka Otake

Tatsuya Yanagi

Kentaro Chikamatsu

Mamoru Tsuruya

Yusuke Nakakohara

Tatsuya Miyazaki

Shinya Takado

Hiroyuki Sakairi

Naotaka Kuroda

Takukazu Otsuka

Toshio Hanada

Hiroaki Ohta

Maiko Hatano

Norikazu Ito

Taketoshi Tanaka

Minoru Akutsu

Yasuo Kanetake

Shigefusa Chichibu

Yuta Okawauchi

Takashi Sawada

Seiya Kitagawa

Shin Egami

A nitride semiconductor module includes a nitride semiconductor device, forming a transistor, and a control circuit. The nitride semiconductor device includes a control electrode arranged on a passivation layer between gate and drain electrodes. The control circuit generates first and second control voltages. The first control voltage, which shifts between a first voltage level and a lower second voltage level, controls a voltage applied between the gate and source electrodes. The second control voltage, which shifts between a third voltage and a lower fourth voltage level, is applied between the control and source electrodes. The control circuit generates the first and second control voltages during a turn-off operation of the transistor so that a shifting completion time of the second control voltage from the third to fourth voltage level is earlier than that of the first control voltage from the first to second voltage level.

Nitride semiconductor module

A nitride semiconductor deviceincludes a first nitride semiconductor layer that constitutes an electron transit layer, a second nitride semiconductor layer that is formed on the first nitride semiconductor layer, is larger in bandgap than the first nitride semiconductor layer, and constitutes an electron supply layer, a gate portion that is formed on the second nitride semiconductor layer, and a source electrode and a drain electrode that, on the second nitride semiconductor layer, are opposingly disposed across the gate portion. The gate portion includes a third nitride semiconductor layer of a ridge shape that is formed on the second nitride semiconductor layer and contains an acceptor type impurity and a gate electrode that is formed on the third nitride semiconductor layer. A film thickness of the third nitride semiconductor layer is greater than 100 nm.

Nitride semiconductor device

A method for manufacturing nitride semiconductor device includes a second step of forming, on a gate layer material film, a gate electrode film that is a material film of a gate electrode, a third step of selectively etching the gate electrode film to form the gate electrodeof a ridge shape, and a fourth step of selectively etching the gate layer material film to form a semiconductor gate layerof a ridge shape with the gate electrodedisposed at a width intermediate portion of a front surface thereof. The third step includes a first etching step for forming a first portionA from an upper end to a thickness direction intermediate portion of the gate electrodeand a second etching step being a step differing in etching condition from the first etching step and being for forming a remaining second portionB of the gate electrode.

Method for manufacturing nitride semiconductor device and nitride semiconductor device

The present invention provides a nitride semiconductor device, including: a silicon substrate; a first lateral transistor over a first region of the silicon substrate and including: a first nitride semiconductor layer formed over the silicon substrate; and a first gate electrode, a first source electrode and a first drain electrode formed over the first nitride semiconductor layer; a second lateral transistor over a second region of the silicon substrate and including: a second nitride semiconductor layer formed over the silicon substrate; and a second gate electrode, a second source electrode and a second drain electrode formed over the second nitride semiconductor layer; a first separation trench formed over a third region; a source/substrate connecting via hole formed over the third region; a first interlayer insulating layer formed over the first source electrode and the second source electrode; and a second interlayer insulating layer formed in the first separation trench.

A nitride semiconductor deviceincludes a first nitride semiconductor layerthat constitutes an electron transit layer, a second nitride semiconductor layerthat is formed on the first nitride semiconductor layer, is larger in bandgap than the first nitride semiconductor layer, and constitutes an electron supply layer, and a gate portionthat is formed on the second nitride semiconductor layer. The gate portionincludes a first semiconductor gate layerof a ridge shape that is disposed on the second nitride semiconductor layerand is constituted of a nitride semiconductor containing an acceptor type impurity, a second semiconductor gate layerthat is formed on the first semiconductor gate layerand is constituted of a nitride semiconductor with a larger bandgap than the first semiconductor gate layer, and a gate electrodethat is formed on the second semiconductor gate layerand is in Schottky junction with the second semiconductor gate layer

A semiconductor device includes: a first transistor provided with an electron transit layer made of a nitride semiconductor, a first gate electrode, a first source electrode, and a first drain electrode; and a second transistor that includes a second gate electrode, a second source electrode, and a second drain electrode. The first gate electrode and the second drain electrode are electrically connected to each other, while the first source electrode and the second source electrode are not electrically connected to each other.

Semiconductor device

A power conversion circuit in which a switching transistor and a synchronous rectifier transistor are connected in series, and a source inductance of the switching transistor is smaller than a source inductance of the synchronous rectifier transistor.

Power conversion circuit, power module, converter, and inverter

A semiconductor chip includes a front surface and a back surface, a source pad, a drain pad and a gate pad on the front surface; a die pad under the semiconductor chip and bonded to the semiconductor chip; a source lead, electrically connected to the die pad; a drain lead and a gate lead, disposed on a periphery of the die pad; and a sealing resin. A plurality of vias for external connection are formed to connect to the source pad. A first subset of the plurality of vias for external connection is disposed along a first side of the source pad, and a second subset of the plurality of vias for external connection is disposed along a second side of the source pad, wherein the first and second sides are arranged adjacent to each other to form a first edge of the source pad.

A power module (PM) includes: an insulating substrate; a semiconductor device disposed on the insulating substrate, the semiconductor device including electrodes on a front surface side and a back surface side thereof; and a graphite plate having an anisotropic thermal conductivity, the graphite plate of which one end is connected to the front surface side of the semiconductor device and the other end is connected to the insulating substrate, wherein heat of the front surface side of the semiconductor device is transferred to the insulating substrate through the graphite plate. There is provide an inexpensive power module capable of reducing a stress and capable of exhibiting cooling performance not inferior to that of the double-sided cooling structures.

Power module and fabrication method of the same, graphite plate, and power supply equipment

A method for measuring a current-voltage characteristic (Id-Vds characteristic) representing the relationship between the drain current Id (or collector current) and the drain-source voltage Vds (or collector-emitter voltage) of a transistor Mincludes setting the drain current Id (or collector current) and the drain-source voltage Vds (or collector-emitter voltage), measuring the gate-source voltage Vgs (or gate-emitter voltage) and the gate current Ig of the transistor Min a switching transient state, and acquiring the current-voltage characteristic (Id-Vds characteristic) of the transistor Mbased on the measurement results of the gate-source voltage Vgs (or gate-emitter voltage) and the gate current Ig.

Method for measuring current-voltage characteristic

A nitride semiconductor deviceincludes a first nitride semiconductor layerthat constitutes an electron transit layer, a second nitride semiconductor layerthat is formed on the first nitride semiconductor layer and constitutes an electron supply layer, a nitride semiconductor gate layerthat is disposed on the second nitride semiconductor layer, has a ridge portionA at least at a portion thereof, and contains an acceptor type impurity, a gate electrodethat is disposed at least on the ridge portion of the nitride semiconductor gate layer, a source electrodethat is disposed on the second nitride semiconductor layer and has a source principal electrode portionA parallel to the ridge portion, and a drain electrodethat is disposed on the second nitride semiconductor layer and has a drain principal electrode portionA parallel to the ridge portion. A length direction of the ridge portion is a [110] direction of a semiconductor crystal structure that constitutes the second nitride semiconductor layer.

The present invention provides a nitride semiconductor device, including an insulating substrate, a substrate over the first surface of the insulating substrate, a first lateral transistor over a first region of the substrate, wherein the first lateral transistor includes a first nitride semiconductor layer formed over the substrate, and a first gate electrode, a first source electrode and a first drain electrode formed over the first nitride semiconductor layer, and a second lateral transistor over a second region of the substrate, wherein the second lateral transistor includes a second nitride semiconductor layer formed over the substrate, and a second gate electrode, a second source electrode and a second drain electrode formed over the second nitride semiconductor layer, and a separation trench formed over a third region, wherein the third region is between the first region and the second region.

An apparatus includes a control device configured to serve as a principal controlling agent in an electric power conversion device incorporating a switching circuit configured to be a bidirectional inverter. The control device is configured to subtract, from a reference signal that is determined in accordance with an operation mode of the electric power conversion device, a multiplied signal obtained by multiplying a control-target current of the switching circuit by a prescribed coefficient to generate, based on a result of the subtraction, a control signal for controlling the bidirectional inverter.

Control device for controlling an electric power conversion device incorporating a bidirectional inverter

A nitride semiconductor deviceincludes a first transistorwhich is constituted of a normally-off transistor and functions as a main transistor and a second transistorwhich is constituted of a normally-on transistor and arranged to limit a gate current of the first transistor. The first transistorincludes a first electron transit layerA constituted of a nitride semiconductor and a first electron supply layerA which is formed on the first electron transit layer and constituted of a nitride semiconductor. The second transistorincludes a second electron transit layerB constituted of a nitride semiconductor and a second electron supply layerB which is formed on the second electron transit layer and constituted of a nitride semiconductor. A gate electrodeand a source electrodeof the second transistorare electrically connected to a gate electrodeof the first transistor

Growing community of inventors

Kyoto, Japan

Hirotaka Otake