Denso Corporation

National Institute of Advanced Industrial Science and Technology

Toyota Jidosha Kabushiki Kaisha

Tohoku University

Chiba University

Mirise Technologies Corporation

Nisshinbo Micro Devices Inc.

Akihiko Teshigahara

Kazuhiko Kano

Morito Akiyama

Kazuki Arakawa

Toshimasa Yamamoto

Yukihiro Takeuchi

Kazushi Asami

Takao Iwaki

Takahiko Yoshida

Masayoshi Esashi

Shuji Tanaka

Toshio Sakakibara

Hiroyuki Wado

Tetsuo Yoshioka

Akiyoshi Asai

Naohiro Ueno

Atsushi Mizutani

Kenya Hashimoto

Megumi Suzuki

Hiroyasu Itou

Nobuaki Kawahara

Junji Ohara

Hideaki Yamada

Keiko Nishikubo

Kunihiro Onoda

Toshihiko Takahata

Kenichi Sakai

Hideo Yamada

Tetsuya Enomoto

Ryuichirou Abe

Naoki Masumoto

Hiroyuki Kuchiji

Toshihiro Kamohara

Kiyokazu Isomura

Tomoyuki Mizutani

Ryuuichirou Abe

A method for manufacturing an element forming wafer includes the steps of: forming a thin layer on a semiconductor wafer having a plurality of chip forming regions; and adjusting stress generated in an element forming portion of the thin layer to have a specified value. The thin layer constitutes an element in each of the plurality of chip forming regions. The step of adjusting the stress includes: arranging a resist on the thin layer; exposing the resist to light using a photomask having openings; forming openings in the resist by developing the resist; and performing ion-implantation using the resist as a mask. The photomask used during the step of exposing the resist to light has a ratio of the openings that is adjusted based on the stress generated in the element forming portion.

Element forming wafer and method for manufacturing the same

A piezoelectric film layered structure includes a base, and a ScAlN film formed on the base. The ScAlN film has an unpaired electron density within a range between 1.7×10electrons/cm, inclusive, and 1.1×10electrons/cm, inclusive.

Piezoelectric film layered structure and method for producing thereof

Provided is a piezoelectric film including an AlN crystal, and a first element and a second element doped to the AlN crystal. The first element is an element having an ionic radius larger than an ionic radius of Al. The second element is an element having an ionic radius smaller than the ionic radius of Al. Also provided are piezoelectric film laminated body including an underlayer and a piezoelectric film including ScAlN, and a method of manufacturing the same. The underlayer has a crystal lattice having six-fold symmetry or three-fold symmetry. Also provided are a piezoelectric film including ScAlN having a laminated structure of a hexagonal crystal and a cubic crystal, and a method of manufacturing the same. The cubic crystal is doped with an element other than trivalent element.

Piezoelectric film, method of manufacturing same, piezoelectric film laminated body, and method of manufacturing same

A piezo-electric element includes a piezo-electric element part, a support part, and a stretchable film. The piezo-electric element part includes a piezo-electric film and electrodes between which the piezo-electric film is sandwiched in a thickness direction. The support part supports a peripheral portion of the piezo-electric element part. The stretchable film is provided in an oscillation region located inside of the peripheral portion of the piezo-electric element part. The stretchable film also has a higher elasticity than that of the piezo-electric element part.

Piezo-electric element

A surface acoustic wave (SAW) sensor includes a surface acoustic wave material and a comb-teeth electrode. The surface acoustic wave material is to be arranged at a place where the surface acoustic wave material is distorted by physical quantity such as stress. The comb-teeth electrode is arranged on the surface of the surface acoustic wave material to excite a surface acoustic wave to the surface acoustic wave material. The surface acoustic wave material has a sapphire board and a ScAlN film arranged on a surface of the sapphire board.

Surface acoustic wave sensor

A piezoelectric thin film is formed through sputtering and consists essentially of scandium aluminum nitride. The carbon atomic content is 2.5 at % or less. When producing the piezoelectric thin film, scandium and aluminum are sputtered simultaneously on a substrate from a scandium aluminum alloy target material having a carbon atomic content of 5 at % or less in an atmosphere where at least nitrogen gas exists. The sputtering may be conducted also by applying an ion beam on an opposing surface of the alloy target material at an oblique angle. Moreover, aluminum and scandium may be also sputtered simultaneously on the substrate from an Sc target material and an Al target material. As a result, a piezoelectric thin film which exhibits excellent piezoelectric properties and a method for the same can be provided.

Piezoelectric thin film and method for producing the same

A method for manufacturing a piezoelectric thin film including an aluminum nitride thin film containing scandium on a substrate, the method includes: sputtering step for sputtering aluminum and scandium under an atmosphere containing at least a nitrogen gas. In the sputtering step in the method according to the present invention, a scandium content rate falls within the range from 0.5% by atom to 50% by atom when a temperature of the substrate falls within the range from 5&#xb0; C. to 450&#xb0; C. during the sputtering step.

Manufacturing method of piezoelectric-body film, and piezoelectric-body film manufactured by the manufacturing method

An angular rate sensor comprises a piezoelectric film having a first and a second surfaces forming an x-y plane and utilizes a perturbation mass coherently vibrating elastic acoustic waves on which a Coriolis force acts when the angular rate sensor undergoes a rotary motion about an x-direction. A first elastic acoustic wave is excited in the piezoelectric film by a driving transducer and a second elastic acoustic wave generated by the Coriolis force proportional to an angular rate of the rotary motion of the angular rate sensor itself is detected by the detecting transducer. The angular rate sensor further comprises at least a first electrode disposed on the first surface of the piezoelectric film for discharging a surface charge caused due to piezoelectric effect at the lower surface of the film in which the first elastic acoustic wave is excited.

Angular rate sensor

A yaw rate sensor has two sets of exciting electrodes, perturbative weights and two sets of detecting electrodes on a surface of a piezoelectric substrate. The exciting electrodes excite first surface acoustic waves transmitted through the surface of the substrate in a propagation direction. The weights are oscillated by the waves and excite a second surface acoustic wave, transmitted through the surface of the substrate in a detection direction orthogonal to the propagation direction, in response to a yaw applied to the weights. The detecting electrodes measure an intensity of the second surface acoustic wave to detect the yaw rate. The sets of exciting electrodes are symmetrically placed with respect to a driving axis extending straight along the propagation direction. The group of weights is symmetric with respect to the driving axis.

Yaw rate sensor using surface acoustic wave

A sensor chip has a substrate and a comb-teeth electrode arranged on the substrate. The sensor chip is fixed to a diaphragm structure to be distorted by receiving pressure, and is fixed to the diaphragm structure only through a predetermined fix area so as to detect the pressure. The fix area is defined on only a part of the sensor chip opposing to the diaphragm structure. The sensor chip is restrained by the diaphragm structure in a direction of transmitting surface acoustic wave. Flexibility of the sensor chip in a perpendicular direction approximately perpendicular to the wave transmitting direction is larger than that in the transmitting direction.

Surface acoustic wave pressure sensor

A piezoelectric thin film of the present invention includes an aluminum nitride thin film that contains scandium. A content ratio of scandium in the aluminum nitride thin film is 0.5 atom % to 50 atom % on the assumption that a total amount of the number of scandium atoms and the number of aluminum atoms is 100 atom %. According to this arrangement, the piezoelectric thin film of the present invention can improve a piezoelectric response while keeping characteristics of elastic wave propagation speed, Q value, and frequency-temperature coefficient that the aluminum nitride thin film has.

Piezoelectric thin film, piezoelectric material, and fabrication method of piezoelectric thin film and piezoelectric material, and piezoelectric resonator, actuator element, and physical sensor using piezoelectric thin film

In a radar apparatus, a radar device emits a transmission wave to a periphery of a vehicle and detects a reflected wave of the transmission wave through a window part. As a member for restricting or reducing adhesion of dirt and foreign materials to the window part, an air duct is provided to apply air toward the window part. An air outlet portion of the air duct is open at a periphery of the window part and has a passage area smaller than that of an air inlet portion, which opens to a vehicle forward direction. While the vehicle is running, air is blown from the air outlet portion to flow along the window part at high speed after its pressure is increased in the air duct. Thus, dirt and materials adhering or adhered to the window part is effectively blown off.

Radar apparatus

A capacitance type physical quantity sensor detects physical quantity. The sensor includes a movable portion including a movable electrode and a fixed portion including a fixed electrode. The fixed electrode includes a detection surface facing a detection surface of the movable electrode. The movable electrode is movable toward the fixed electrode in accordance with the physical quantity so that a distance between the detection surfaces is changeable. At least one of the movable and the fixed electrodes includes a groove. The groove is disposed on a top or a bottom of the one of the movable and the fixed electrodes, has a predetermined depth from the top or the bottom, and extends from the detection surface to an opposite surface.

Capacitance type physical quantity sensor

A flow sensor for detecting flow of fluid includes a thin film portion. The thin film portion has a heater and a detector for detecting temperature around the heater. The heater is made of semiconductor. This flow sensor has high sensor sensitivity with low energy consumption. Further, the sensor has high detection accuracy, and the thin film portion has high endurance. Furthermore, the flow sensor with a passivation film has appropriate thickness so as to improve strength of a thin film portion.

Flow sensor having thin film portion and method for manufacturing the same

Growing community of inventors

Nisshin, Japan

Akihiko Teshigahara