Kabushiki Kaisha Toshiba

Naoko Yanase

Takaaki Yasumoto

Ryoichi Ohara

Kenya Sano

Kazuhiko Itaya

Takashi Kawakubo

Kazuhide Abe

Michihiko Nishigaki

Toshihiko Nagano

Shingo Masuko

Akira Yoshioka

Hidetoshi Fujimoto

Masahiko Hasunuma

Hiroshi Toyoda

Yasunobu Saito

Toshiyuki Naka

Tetsuya Ohno

Takako Motai

Hironobu Shibata

Takeshi Uchihara

Tasuku Ono

Takao Noda

Yorito Kakiuchi

Tatsuo Shimizu

Hiroshi Yoshida

Keiichi Yamaguchi

Atsuko Iida

Nobuyuki Itoh

Tadahiro Sasaki

Mayumi Morizuka

Ryuichi Fujimoto

Miki Yumoto

Masaru Furukawa

Yukako Murakami

Tooru Kozu

Takeshi Ookubo

Yasunari Yagi

A semiconductor device includes a GaN-based semiconductor layer, a source electrode on the GaN-based semiconductor layer, a drain electrode on the GaN-based semiconductor layer, and a gate electrode formed on the GaN-based semiconductor layer between the source electrode and the drain electrode. A first layer is in contact with the GaN-based semiconductor layer between the gate electrode and the drain electrode.

Semiconductor device

According to an embodiment, a semiconductor device includes a conductive substrate, a Schottky barrier diode, and a field-effect transistor. The Schottky barrier diode is mounted on the conductive substrate and includes an anode electrode and a cathode electrode. The anode electrode is electrically connected to the conductive substrate. The field-effect transistor is mounted on the conductive substrate and includes a source electrode, a drain electrode, and a gate electrode. The source electrode of the field-effect transistor is electrically connected to the cathode electrode of the Schottky barrier diode. The gate electrode of the field-effect transistor is electrically connected to the anode electrode of the Schottky barrier diode.

In one embodiment, a semiconductor device includes a first semiconductor layer of a first conductivity type or an intrinsic type. The device further includes a second semiconductor layer of the first conductivity type or the intrinsic type disposed above the first semiconductor layer. The device further includes a third semiconductor layer of a second conductivity type including a first upper portion in contact with the first semiconductor layer, a second upper portion located at a lower position than the first upper portion, a first side portion located between the first upper portion and the second upper portion, and a second side portion located at a lower position than the first side portion.

HEMT semiconductor device

According to one embodiment, a semiconductor device includes a SiC layer of a first conductivity type, a SiC region of a second conductivity type, and a conductive layer of the second conductivity type. The SiC layer of the first conductivity type has a hexagonal crystal structure. The SiC region of the second conductivity type is formed in a surface of the SiC layer. The conductive layer of the second conductivity type is provided on the SiC region and is in contact with a portion of the SiC region including SiC of a cubic crystal structure.

Semiconductor device and method for manufacturing semiconductor device

A piezoelectric thin film device includes an amorphous metal film disposed on a substrate and a piezoelectric film disposed on the amorphous metal. One of crystal axis of the piezoelectric film is aligned in a direction perpendicular to a surface of the amorphous metal.

Piezoelectric thin film device and method for manufacturing the same

A thin film piezoelectric resonator includes a substrate having a cavity; a first electrode extending over the cavity; a piezoelectric film placed on the first electrode; and a second electrode placed on the piezoelectric film, the second electrode having a periphery partially overlapping on the cavity and tapered to have an inner angle of 30 degrees or smaller defined by a part of the periphery thereof and a bottom thereof.

Thin film piezoelectric resonator and method of manufacturing the same

A thin-film piezoelectric resonator includes a substrate, and first and second excitation portions. The substrate includes first and second cavities. The first excitation portion is disposed over the first cavity, and includes a first electrode, a first piezoelectric material and a second electrode laminated successively. An overlapping region among the first electrode, the first piezoelectric material and the second electrode defines a contour of a periphery of the first excitation portion. A first distance is defined as a distance from an end of the first excitation portion to an opening end of the first cavity. The second excitation portion is disposed over the second cavity, and includes a third electrode, a second piezoelectric material and a fourth electrode laminated successively. A second distance is defined as a distance from an end of the second excitation portion to an opening end of the second cavity and different from the first distance.

Thin-film piezoelectric resonator, filter and voltage-controlled oscillator

A piezoelectric thin film resonator includes a substrate in which a cavity is formed, a first electrode having a first electrode edge and partly spanning the cavity on the substrate; a piezoelectric layer placed on the first electrode, a second electrode having a second electrode edge and placed on the piezoelectric layer, a resonator unit constituted by an overlapping part of the first electrode, the piezoelectric layer, the second electrode, and the cavity; and a second lead wiring which is integral with the second electrode, extends to the substrate where the cavity is not present, and has a width larger than a part of a peripheral length of the cavity to which the second electrode edge extends. In the piezoelectric thin film resonator, a first length defined by the periphery of the first electrode of the resonator unit is larger than a second length defined by the second electrode edge of the resonator unit.

Piezoelectric thin film resonator and devices provided with the same

A film bulk acoustic-wave resonator encompasses a substrate having a cavity; a bottom electrode partially fixed to the substrate, part of the bottom electrode is mechanically suspended above the cavity; a piezoelectric layer provided on the bottom electrode; and a top electrode provided on the piezoelectric layer having crystal axes oriented along a thickness direction of the piezoelectric layer, a full width at half maximum of the distribution of the orientations of the crystal axes is smaller than or equal to about six degrees.

Film bulk acoustic-wave resonator (FBAR), filter implemented by FBARs and method for manufacturing FBAR

A film bulk acoustic-wave resonator having, a substrate having a cavity, the substrate being formed of one of semi-insulating material and high-resistivity material, a bottom electrode partially fixed to the substrate, part of the bottom electrode is mechanically suspended above the cavity, a piezoelectric layer disposed on the bottom electrode, the shape of the piezoelectric layer is defined by a contour, a top electrode on the piezoelectric layer, a semiconductor intermediate electrode buried at and in a surface of the substrate, being located at the contour of the piezoelectric layer, the semiconductor region having a lower resistivity than the substrate, the intermediate electrode is connected to the bottom electrode in the inside of the contour, and a bottom electrode wiring connected to the semiconductor intermediate electrode extending from the contour to an outside of the contour in the plan view.

Film bulk acoustic-wave resonator and method for manufacturing the same

A voltage controlled oscillator includes a resonator configured to resonate with an initial oscillation frequency during starting period of oscillation and a steady oscillation frequency during a steady state oscillation. The resonator includes a film bulk acoustic resonator having a series resonance frequency higher than the steady oscillation frequency. A negative resistance circuit configured to drive the resonator, has a positive increment for reactance in the steady state oscillation compared with reactance in the starting period.

Voltage controlled oscillator, frequency synthesizer and communication apparatus

A film bulk acoustic-wave resonator encompasses (a) a substrate having a cavity, (b) a bottom electrode partially fixed to the substrate, part of the bottom electrode is mechanically suspended above the cavity, (c) a piezoelectric layer disposed on the bottom electrode, a planar shape of the piezoelectric layer is defined by a contour, which covers an entire surface of the bottom electrode in a plan view, (d) a top electrode on the piezoelectric layer, (e) an intermediate electrode located between the substrate and the piezoelectric layer, and at the contour of the piezoelectric layer, the intermediate electrode is connected to the bottom electrode in the inside of the contour, and (f) a bottom electrode wiring connected to the intermediate electrode extending from the contour to an outside of the contour in the plan view, wherein a longitudinal vibration mode along a thickness direction of the piezoelectric layer is utilized.

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Kawasaki, Japan

Naoko Yanase