1652 results about "Piezoelectric thin films" patented technology

A micro-electrical-mechanical system (MEMS) vibrating structure includes a carrier substrate, a first anchor, a second anchor, a single crystal piezoelectric body, and a conducting layer. The first anchor and the second anchor are provided on the surface of the carrier substrate. The single-crystal piezoelectric body is suspended between the first anchor and the second anchor, and includes a uniform crystalline orientation defined by a set of Euler angles. The single-crystal piezoelectric body includes a first surface parallel to and facing the surface of the carrier substrate on which the first anchor and the second anchor are formed and a second surface opposite the first surface. The conducting layer is inter-digitally dispersed, and is formed on the second surface of the single-crystal piezoelectric body. The first surface of the single-crystal piezoelectric body is left exposed.

A piezoelectric resonant filter includes a group of series resonators and a group of parallel resonators for forming a ladder-type filter circuit. Each of the resonators has a piezoelectric thin film having piezoelectric characteristic, and lower and upper electrodes disposed on opposite surfaces of the piezoelectric thin film for applying an excitation voltage to the piezoelectric thin film. The group of the parallel resonators exhibits a low frequency side attenuation extremum in the filter whereas the group of the series resonators exhibits a high frequency side attenuation extremum in the filter. At least one of the group of the series resonators and the group of the parallel resonators has a temperature compensating layer for bringing the temperature coefficient of the resonant frequency close to zero.

An electrostatic self-assembly method of fabricating electrostrictive and piezoelectric thin film assemblies not only provides a thinner film than is attainable by conventional methods, but provides excellent molecular-level uniformity and precise structural control, and thus large, effective piezoelectric coefficients. The method produces a thin film assembly including (a) a substrate, and (b) a film having one or a plurality of layers disposed upon the substrate, wherein at least one of the layers includes a dipolar material, and this layer of dipolar material has a uniform thickness of at most 500 nm.

Surface acoustic wave device having a high k<2>, and a frequency filter, oscillator, electronic circuit and electronic device employing this surface acoustic wave device is provided, wherein a first oxide thin film layer comprising SrO or MgO and a second oxide thin film layer comprising SrTiO3 are sequentially formed on top of a (110) Si substrate, or a first oxide thin film layer comprising CeO2, ZrO2 or yttrium-stabilized zirconia and a second oxide thin film layer comprising SrTiO3 are sequentially formed on top of a (100) Si substrate, a KNbO3 piezoelectric thin film being then formed on top of either of these second oxide thin film layers, and then, a protective film comprising oxide or nitride is formed on top of the KNbO3 piezoelectric thin film, finally, at least one electrode is formed on top of this protective film, to form a surface acoustic wave device, which surface acoustic wave device is employed to form a frequency filter, oscillator, electronic circuit, or electronic device.

A piezoelectric thin film sensor array is used to scan and capture biometric data, for example, a fingerprint image. In one embodiment, a multi-layer structure includes a PVDF layer in between two conductor grids arranged orthogonally to one another. Urethane can be added to one side where a finger is placed. A foam substrate can be used as a support. In one feature, the PVDF, and grids can be peeled off like a label for easy replacement. Multiplexers are switched to scan the sensor. A single pixel or a group of pixels can be detected and output to an image memory. The presence of a fingerprint ridge is detected by virtue of a ring-down oscillation that arises from reflection when an electric field is applied to the piezoelectric thin film sensor array at a pixel in contact with the fingerprint ridge. For example, such a ring-down value associated with a fingerprint ridge can be detected at about 150 ns. (or 5 cycles at 30 MHZ). Other reflections indicative of additional biometrics (e.g. from tissue, blood, bone, fingernail, etc.) can also be detected. A Doppler effect due to reflections from circulating blood can also be detected. Such a Doppler effect can provide further information about direction and speed of blood circulation. An instantaneous pyroelectric effect can also be detected to indicate a live finger presence.

a thin film piezoelectric resonator includes a substrate having a cavity, and a resonance portion located on the substrate and right above the cavity. The resonance portion includes a lower electrode layer located at a side of the cavity, an upper electrode layer opposite to the lower electrode layer, and a piezoelectric thin film located between the upper electrode layer and the lower electrode layer. A side of the piezoelectric thin film and a side of the lower electrode layer are located in a common plane.

A piezoelectric resonator that achieves stable quality and improved resonance characteristics includes an acoustic reflector portion disposed between a substrate and a vibration portion, which includes a piezoelectric thin film sandwiched between a pair of electrodes, and a plurality of low acoustic impedance layers made of a material having relatively low acoustic impedance and a plurality of high acoustic impedance layers formed made of a material having relatively high acoustic impedance, the acoustic impedance layers being disposed alternately, and adjustment layers, which are disposed between the high acoustic impedance layers and the low acoustic impedance layers on the substrate sides of the high acoustic impedance layers and which have an acoustic impedance value intermediate between that of the high acoustic impedance layers and that of the low acoustic impedance layers. The low acoustic impedance layers and the high acoustic impedance layers have compressive stresses and the adjustment layers have a tensile stress.

A method for making a micro-electro-mechanical systems (MEMS) vibrating structure is disclosed. The MEMS is supported by a MEMS anchor system and includes a single-crystal piezoelectric thin-film layer that has a specific non-standard crystal orientation, which may be selected to increase an electromechanical coupling coefficient, decrease a temperature coefficient of frequency, or both. The MEMS vibrating structure may have dominant lateral vibrations or dominant thickness vibrations. The single-crystal piezoelectric thin-film layer may include Lithium Tantalate or Lithium Niobate, and may provide MEMS vibrating structures with precise sizes and shapes, which may provide high accuracy and enable fabrication of multiple resonators having different resonant frequencies on a single substrate.

A piezoelectric thin-film resonator includes a supporting substrate. A piezoelectric thin-film is formed on the supporting substrate. A lower electrode and an upper electrode are formed with the piezoelectric thin-film therebetween. The stiffness of at least one of the lower and upper electrodes is higher than that of the piezoelectric thin-film.

An elastic wave device includes a support layer with a through-hole or a recess opened at an upper surface thereof, a piezoelectric thin film arranged on the support layer to extend above the recess or the through-hole of the support layer, and an IDT electrode defined on at least one of upper and lower surfaces of the piezoelectric thin film in a region of the piezoelectric thin film, the region extending above the recess, or the through-hole. A secondary mode of a plate wave, which contains a U1 component as a main component, is utilized. The piezoelectric thin film is made of LiTaO3, and Euler angles (φ, θ, ψ) of the LiTaO3 fall within specific ranges.

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.

There is provided a lamb wave device with small variations in frequency, the device including: a piezoelectric thin film; an IDT electrode which is provided on a main surface of the piezoelectric thin film; and a support structure which supports a laminate of the IDT electrode and the piezoelectric thin film, and is formed with a cavity that isolates the laminate, wherein a film thickness h of the piezoelectric thin film and a pitch p of a finger of the IDT electrode are selected such that a lamb wave is excited at a target frequency, the lamb wave making dispersibility of a sonic velocity v with respect to the film thickness h of the piezoelectric thin film small.

The present invention relates to a micro-electro-mechanical systems (MEMS) vibrating structure having dominant lateral vibrations supported by a MEMS anchor system, and includes a single-crystal piezoelectric thin-film layer that has been grown with a specific crystal orientation. Since the MEMS vibrating structure has dominant lateral vibrations, its resonant frequency may be controlled by its size and shape, rather than layer thickness, which provides high accuracy and enables multiple resonators having different resonant frequencies on a single substrate.

A piezoelectric thin film resonator has a substrate and a piezoelectric layered structure including a lower electrode, piezoelectric aluminum nitride thin film with c-axis orientation and upper electrode formed on the substrate in this order. The lower electrode are made of a metal thin film including a layer containing ruthenium as a major component having a full-width half maximum (FWHM) of a rocking curve of a (0002) diffraction peak of ruthenium of 3.0° or less. The piezoelectric aluminum nitride thin film formed on the lower electrode has a full-width half maximum (FWHM) of a rocking curve of a (0002) diffraction peak of 2.0° or less.

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.