Rohm Co., Ltd.

Other

National Institute of Advanced Industrial Science and Technology

Ken Nakahara

Norikazu Ito

Shigeru Niki

Shunsuke Akasaka

Paul Fons

Kakuya Iwata

Kenji Yamamoto

Minoru Akutsu

Tetsuya Fujiwara

Tetsuhiro Tanabe

Atsushi Yamaguchi

Yusuke Nakakohara

Koji Matsubara

Akimasa Yamada

Yuta Okawauchi

Kentaro Tamura

Masashi Kawasaki

Hidemi Takasu

Akira Ohtomo

Atsushi Tsukazaki

Taketoshi Tanaka

Mitsuhiko Sakai

Koki Sakamoto

Tetsuo Fujii

Yurina Amamoto

Soichiro Arimura

Hiroyuki Yuji

Shunsuke Furuse

Masahide Tanaka

Takashi Nakamura

Haruo Tanaka

Yoshikazu Fujimori

Hiroyuki Sakairi

Masayuki Sonobe

Tsuyoshi Tsutsui

Tetsuya Yamamoto

Koji Terumoto

Kazuaki Tsutsumi

Jun Ichihara

Daisuke Niwa

Tadahiro Okazaki

Junichi Kashiwagi

Kazuhiro Oguchi

Yohei Moriyama

Hisayoshi Kitajima

Shinichi Tamai

Masayuki Kitagawa

Keisuke Wakamoto

Shinichiro Nagai

Yuji Hiroyuki

Yuuki Ootabara

A nitride semiconductor device includes an electron transit layer, an electron supply layer that is formed on the electron transit layer, a gate layer that is formed on the electron supply layer and contains an AlGaN (0<X<1) based material containing a first impurity, a gate electrode that is formed on the gate layer and is in Schottky junction with the gate layer, and a source electrode and a drain electrode that are electrically connected to the electron supply layer. By this arrangement, a gate withstand voltage can be improved and therefore, a nitride semiconductor device of high reliability can be provided.

Nitride semiconductor device

A nitride semiconductor device includes an electron transit layer that is formed of a nitride semiconductor, an electron supply layer that is formed on the electron transit layer, and formed of a nitride semiconductor and that has a recess which reaches the electron transit layer from a surface, a thermal oxide film that is formed on the surface of the electron transit layer exposed within the recess, a gate insulating film that is embedded within the recess so as to be in contact with the thermal oxide film, a gate electrode that is formed on the gate insulating film and that is opposite to the electron transit layer across the thermal oxide film and the gate insulating film, and a source electrode and a drain electrode that are provided on the electron supply layer at an interval such that the gate electrode intervenes therebetween.

Nitride semiconductor device and fabrication method therefor

A semiconductor device includes a conductive member including first, second and third conductors mutually spaced, a first semiconductor element having a first obverse surface provided with a first drain electrode, a first source electrode and a first gate electrode, and a second semiconductor element having a second obverse surface provided with a second drain electrode, a second source electrode and a second gate electrode. The first conductor is electrically connected to the first source electrode and the second drain electrode. The second conductor is electrically connected to the second source electrode. As viewed in a first direction crossing the first obverse surface, the second conductor is adjacent to the first conductor in a second direction crossing the first direction. The third conductor is electrically connected to the first drain electrode and is adjacent to the first conductor and the second conductor as viewed in the first direction.

Semiconductor device

A gas concentration measurement system includes a limiting current-type gas sensor, a voltage source connected to the limiting current-type gas sensor, a current detector connected to the limiting current-type gas sensor, and a gas concentration arithmetic unit connected to the current detector. The voltage source supplies first and second voltages to the limiting current-type gas sensor. The first and second voltages generate first and second limiting currents corresponding to first and second gases, respectively, in the limiting current-type gas sensor. The current detector acquires first and second limiting current values of the limiting current-type gas sensor when the first and second voltages are applied to the limiting current-type gas sensor, respectively. The gas concentration arithmetic unit includes a difference acquiring section that acquires a difference between the second and first limiting current values and a gas concentration acquiring section that obtains concentration of the second gas based on the difference.

Gas concentration measurement system and gas concentration measurement method

A nitride semiconductor device includes an electron transit layer () that is formed of a nitride semiconductor, an electron supply layer () that is formed on the electron transit layer (), that is formed of a nitride semiconductor whose composition is different from the electron transit layer () and that has a recess () which reaches the electron transit layer () from a surface, a thermal oxide film () that is formed on the surface of the electron transit layer () exposed within the recess (), a gate insulating film () that is embedded within the recess () so as to be in contact with the thermal oxide film (), a gate electrode () that is formed on the gate insulating film () and that is opposite to the electron transit layer () across the thermal oxide film () and the gate insulating film (), and a source electrode () and a drain electrode () that are provided on the electron supply layer () at an interval such that the gate electrode () intervenes therebetween.

Disclosed is a thermal flow sensor including a base member and a cover. The base member includes a heater. The cover is formed by an SOI substrate including a silicon substrate, a silicon dioxide film, and a silicon film. The silicon film has a recessed portion defined therein. A main flow passage portion is defined by an exposed surface of the silicon dioxide film which is exposed from the silicon film and which defines a bottom surface of the recessed portion, the silicon film defining a side surface of the recessed portion, and a first principal surface of the cover.

Thermal flow sensor

A gate drive circuit, which drives a gate of a first transistor, includes a first switch on a high potential side and a second switch on a low potential side connected in series at a second connection node between a high potential end and a low potential end of a series connection structure, constituted of a first voltage source and a second voltage source connected in series at a first connection node; and a third switch and an inductor connected in series between the first connection node and the second connection node. The gate of the first transistor can be electrically connected to the second connection node.

Gate drive circuit

A negative voltage generation circuitincludes a first DC voltage sourcehaving a positive terminal connected to a first node N(Vin), a first diodehaving a cathode connected to a negative terminal of the first DC voltage sourceand an anode connected to an output terminal of a first negative voltage VC(fourth node N), and a first capacitorhaving a first terminal connected to an output terminal of the first negative voltage VCand a second terminal connected to a second node N(Vs_high), so as to supply the first negative voltage VCto a first driverthat performs switching control of a first NMOSFET(first switch element) connected between the first node N(Vin) and the second node N(Vs_high).

Negative voltage generation circuit and power conversion device using same

A nitride semiconductor device includes a first impurity layer made of an AlGaN (0&#x3c;X&#x2264;1) based material and containing a first impurity with which a depth of an acceptor level from a valence band (E-E) is made not less than 0.3 eV but less than 0.6 eV, an electron transit layer formed on the first impurity layer, an electron supply layer formed on the electron transit layer, agate electrode formed on the electron transit layer, and a source electrode and a drain electrode formed such that the source electrode and the drain electrode sandwich the gate electrode and electrically connected to the electron supply layer.

A ripple injection circuit equipped with: a capacitor that passes a frequency component of an input voltage or a frequency component of an output voltage and that generates a first ripple voltage having a first ripple component; and an integration circuit that integrates a comparison result signal and that generates a second ripple voltage having a second ripple component. The first ripple component and the second ripple component are added to a feedback voltage.

Ripple injection circuit and electronic device equipped with this circuit

Growing community of inventors

Kyoto, Japan

Ken Nakahara