91 results about "Piezoelectric mems" patented technology

A piezoelectric valve comprising: a fixed portion defining an opening; and a number of movable portions extending from the fixed portion over the opening and separated from one another by radially oriented slits, each movable portion of the number of movable portions comprising a first material layer and a second material layer, and at least one of the first material layer or the second material layer comprises a piezoelectric material that is operable to drive a displacement of the movable portion in a direction opposite to an adjacent movable portion sharing a same radially oriented slit upon application of a voltage.

The present invention relates to the fields of ferroelectric single crystal technology and acousto-optical device technology, particularly to a silicon-based lead magnesium niobate (PbMn) single crystal piezoelectric wafer structure, preparation method, and application. The structure comprises a silicon substrate on which a silicon dioxide layer and a single crystal piezoelectric thin film layer are sequentially disposed; the single crystal piezoelectric thin film layer is a PbMn-PT single crystal, including a binary PMN-PT single crystal thin film or a ternary PIN-PMN-PT single crystal thin film. This piezoelectric wafer structure on a silicon substrate can be used to fabricate various high-performance piezoelectric MEMS sensors, actuators, and electro-optical modulator devices. The resulting surface acoustic wave (SAW) filters and thin film bulk acoustic wave (BAW) filters exhibit a relative bandwidth increase of over 50%, and the resulting electro-optical modulators exhibit lower half-wave voltage and higher electro-optical modulation efficiency. The device volume can be reduced by 10 times, better meeting the future 6G communication requirements for higher efficiency, higher integration, and miniaturization of MEMS devices. This provides a novel multilayer piezoelectric wafer structure for the miniaturization and integration of piezoelectric MEMS and optoelectronic devices.

The utility model provides a piezoelectric MEMS accelerometer and a piezoelectric vector hydrophone, and belongs to the technical field of sound wave sensing. The piezoelectric MEMS accelerometer comprises a base body, wherein the middle part of the base body is provided with a cylindrical through area; the mass block is cylindrical and is arranged in the through area, and an annular area is formed between the mass block and the base body; the multiple cantilever beams are evenly arranged in the annular area in the circumferential direction of the mass block, the two ends of each cantilever beam are connected with the mass block and the base body respectively, each cantilever beam comprises a substrate layer, a lower electrode layer, a piezoelectric layer and an upper electrode layer which are sequentially stacked, a through hole used for exposing the lower electrode layer is formed in the piezoelectric layer, and a through hole used for exposing the upper electrode layer is formed in the upper electrode layer. The upper electrode layer comprises an inner electrode and an outer electrode which are arranged at intervals in the radial direction of the mass block, and the inner electrode and the outer electrode are located in opposite cantilever beam deformation areas. The piezoelectric MEMS accelerometer provided by the utility model is adjustable in sensitivity and flexible to use.

A piezoelectric microelectromechanical systems device can include a cavity bounded by walls and an asymmetrical bimorph structure at least partially spanning the cavity that includes at least a piezoelectric layer and two electrode layers. The electrode layers can have relative thicknesses configured to compensate for expected temperature stress in the bimorph structure. Thus, metals having different thicknesses can be positioned and configured to compensate deflection due to thermal stress of any or all of the piezoelectric layer, the first metal layer, and second metal layer and a substrate. A method for making the piezoelectric microelectromechanical systems device is also provided.

The invention discloses a fixed end beam-cantilever beam type piezoelectric MEMS loudspeaker and a preparation method and application thereof. The piezoelectric MEMS loudspeaker comprises a substrate, an upper electrode, a piezoelectric layer, a lower electrode and a vibrating membrane, the upper electrode, the piezoelectric layer and the lower electrode are sequentially arranged on the substrate, and the vibrating membrane and an etching gap surrounding the vibrating membrane are formed on the upper electrode, the piezoelectric layer and the lower electrode in an etching mode; the vibration displacement of the fixed end beam-cantilever beam type piezoelectric MEMS loudspeaker is very large, and is mainly attributed to the superposition of the vibration displacement of the fixed end beam and the vibration displacement of the cantilever beam.

The invention provides a packaging structure for a piezoelectric MEMS resonator and an electronic component, and belongs to the field of semiconductor devices.The packaging structure comprises a device wafer, a cap wafer, a first insulating layer and a metal layer, and the first insulating layer and the metal layer are arranged on the cap wafer. The substrate layer comprises a substrate area and a first resonance cavity area surrounded by the substrate area; the device silicon layer, the first dielectric layer, the piezoelectric layer and the top electrode layer are arranged on the substrate layer; the cap wafer comprises a cap layer; the first annular isolation groove is formed in the cap layer, and the first annular isolation groove is filled with a second dielectric layer; wherein the surface, bonded with the cap wafer, of the device wafer is the surface, far away from the substrate layer, of the device silicon layer, the surface, bonded with the device wafer, of the cap wafer is the surface, far away from the first insulating layer, of the cap layer, and the cap layer is made of low-resistance monocrystalline silicon. According to the packaging structure, the packaging vacuum degree can be effectively improved, and the working performance of the resonator is improved.

The invention discloses a piezoelectric MEMS loudspeaker based on a folding ring between movable and fixed parts and application thereof, and belongs to the technical field of loudspeakers, the piezoelectric MEMS loudspeaker comprises a piezoelectric actuating assembly, a fixed assembly and a folding ring; the piezoelectric actuating assembly comprises a piezoelectric actuating composite layer, the piezoelectric actuating composite layer at least comprises a piezoelectric material layer, and the piezoelectric actuating composite layer generates mechanical displacement by applying voltage to drive the piezoelectric actuating assembly to vibrate so as to generate sound pressure; the fixing component can be a single structural component or a component with a plurality of structural components; the fixing assembly can be used for fixedly supporting the fixed supporting part of the piezoelectric actuating assembly, so that the non-fixed supporting part of the piezoelectric actuating assembly can freely move or vibrate; according to the invention, through the innovative design based on the folding ring between the moving part and the fixed part, the low-frequency vibration displacement of the vibrating diaphragm is remarkably improved, the problem that the low-frequency sound pressure of a traditional piezoelectric MEMS loudspeaker is insufficient is effectively solved, and the vibrating diaphragm can push air with a larger volume in a low-frequency band, so that a fuller low-frequency sound effect is obtained.

The present invention specifically relates to a method for preparing a piezoelectric MEMS smart speaker, including: using a theoretical formula for film vibration frequency to preliminarily calculate the film vibration frequency according to a target frequency range; using finite element analysis software to perform simulation and predict the resonance frequency of each vibration membrane to determine the material of each layer; selecting a piezoelectric material; selecting a substrate material; sputtering a first electrode material on the substrate, and etching to form a required electrode pattern; depositing a piezoelectric layer material to ensure uniform thickness; sputtering a second electrode material on the piezoelectric layer, and etching to form a required electrode pattern; testing the actual performance frequency of the speaker; adjusting the thickness or shape of the piezoelectric layer according to the test results; and also including using a dynamic algorithm to adjust the thickness or shape of the piezoelectric layer; re-depositing the piezoelectric layer and adjusting it; until the resonance frequencies of all vibration membranes are within the target range.

This application relates to the field of acoustic transducers, and particularly to a high-sensitivity MEMS acoustic device and its fabrication method. The high-sensitivity MEMS acoustic device is composed of an upper electrode layer, a piezoelectric layer, a lower electrode layer, a passive layer, an insulating layer, and a substrate connected in sequence. The multilayer composite film is radially symmetrical on the passive layer. A slit through the center of radial symmetry divides the composite film into several partitions. The upper and lower electrode layers of each partition are respectively provided with pads for signal extraction. The voltage signals of the pads in each partition are extracted through series or parallel connection. This application increases the output voltage by dividing the piezoelectric sensitive composite film into multiple sensitive regions and combining the sensitive regions in series, antiphase superposition, or other forms, thereby improving the sensitivity of the piezoelectric MEMS device.

A piezoelectric microelectromechanical systems microphone is provided comprising a substrate including at least one wall defining a cavity, the at least one wall defining an anchor region around a perimeter, a piezoelectric film layer forming a membrane, the piezoelectric film layer being supported at the anchor region by a spring region, and an electrode disposed over the piezoelectric film layer. A method of manufacturing such a MEMS microphone is also provided.

There is provided a piezoelectric microelectromechanical systems microphone comprising a sensor including at least one piezoelectric layer, at least one constraint in contact with the sensor at a position, such that the sensor is supported by the at least one constraint, and such that the sensor that the sensor has a membrane region to one side of the at least one constraint and a cantilevered region to the other side of the at least one constraint and a cavity defined at least partially by the at least one constraint. There is also provided a method of manufacturing the microphone.

A piezoelectric MEMS loudspeaker. The application discloses a MEMS structure, comprising: a substrate comprising an inner ring body and an outer ring body connected by a connecting rod, having a first cavity between the inner ring body and the outer ring body, and having a second cavity in the inner ring body; a piezoelectric composite vibration layer formed above the substrate, comprising an edge portion formed above the outer ring body and a center portion formed above the inner ring body, having a partition gap between the edge portion and the center portion. In summary, the piezoelectric MEMS loudspeaker provided by the application comprises an edge portion and a center portion, wherein the edge portion is used to generate a high-frequency sound pressure level, and the center portion is used to generate a low-frequency sound pressure level. The combination of the edge portion and the center portion makes the piezoelectric MEMS loudspeaker have a relatively flat sound pressure level frequency response curve with a wider range, thereby improving the auditory effect in the entire frequency band.

The application discloses a piezoelectric MEMS device preparation process and a device structure, and relates to the technical field of piezoelectric MEMS device preparation. The preparation process comprises the following steps: forming a groove near an edge region on a front surface of a substrate, depositing a sacrifice layer on the front surface of the substrate and patterning the sacrifice layer, so that the sacrifice layer is separated into a center region and an edge support region, forming a piezoelectric-buffer stack on the sacrifice layer and patterning the piezoelectric-buffer stack, and opening a release hole, the release hole being communicated with the center region of the sacrifice layer, introducing etching medium into the release hole to remove the center region of the sacrifice layer, and then etching a back cavity on the back surface of the substrate. The application limits the size of a diaphragm region through the groove, etches the back cavity of the substrate after the sacrifice layer is released, and compared with a traditional method of defining the diaphragm by etching the back cavity, the application completely avoids the size error of the diaphragm caused by the angle deviation of deep silicon etching, accurately locks the profile of the diaphragm, and greatly improves the size consistency and performance stability of devices in the same batch.

The application discloses a piezoelectric MEMS loudspeaker and a performance improvement method thereof, and belongs to the field of MEMS loudspeakers. The application first proposes a cantilever beam structure with a fixed support end perforation, and the structure can change the resonant frequency of the device. Further, based on the structure, the piezoelectric MEMS loudspeaker proposed in the application is composed of a plurality of triangular cantilever beams with different fixed support end perforations. Since the displacement of the triangular cantilever beam at the resonant frequency will be phase-inverted, the driving voltages of various triangular cantilever beams at both sides of the respective resonant frequencies should be opposite. Through the optimization design of the cantilever beam structure, compared with the traditional piezoelectric MEMS loudspeaker, the application can improve the sound pressure level output at the design frequency band without additional process difficulty, make the sound pressure level spectrum curve in the human ear hearing threshold frequency band relatively flat, realize compact layout, and has a good application prospect.

An acoustic sensor (e.g., for use in a piezoelectric MEMS microphone) includes a substrate and a cantilever beam attached to the substrate. The cantilever beam has a proximal portion attached to the substrate and extends to a distal tip at a free end thereof. The cantilevered beam has a multilayer structure with a plurality of piezoelectric layers and a plurality of metal electrode layers, at least a portion of one of the piezoelectric layers interposed between two metal electrode layers. One or more direct current voltage sources are electrically connected to one or more of the plurality of metal electrode layers and configured to apply a direct current bias voltage between at least two of the plurality of metal electrode layers to deflect the cantilever beam to at least partially counteract a deflection of the cantilever beam due to a residual stress in the cantilever beam.

Systems and techniques are provided for fabrication of piezoelectric MEMS devices to improve performance. For example, an apparatus can include a support stack including a substrate and a modified piezoelectric layer formed on or above the support stack. The modified piezoelectric layer includes a material structure modified by non-equilibrium thermal process to increase an average grain size within the material structure of the modified piezoelectric layer. In some implementations, the modified piezoelectric layer includes an aluminum nitride (AlN) crystalline lattice where at least a portion of aluminum in the AlN crystalline lattice are replaced with scandium forming aluminum scandium nitride (AlScN).

The application discloses a piezoelectric MEMS sensor, comprising: a substrate having a cavity; a vibration support layer formed above the substrate and covering the cavity; a lower electrode layer formed above the vibration support layer; a piezoelectric layer formed above the lower electrode layer; and an upper electrode layer having a groove and the groove divides the upper electrode layer into a center electrode layer and an outer ring electrode layer; wherein, in a first case, a first pad of the center electrode layer is used to output a first electric signal, and a second pad of the outer ring electrode layer is grounded to compensate for the voltage generated by the pyroelectric effect of the piezoelectric MEMS sensor; or in a second case, the first pad of the center electrode layer is used to output a second electric signal, the second pad of the outer ring electrode layer is used to output a third electric signal, and the lower electrode layer is grounded. The piezoelectric MEMS sensor effectively eliminates the voltage generated by the pyroelectric effect and improves the output voltage generated by the pressure difference.

The application belongs to the field of piezoelectric MEMS sensors, and relates to a piezoelectric MEMS ultrasonic sensor ranging circuit and a ranging method, which comprise an MCU, a high-voltage pulse driving circuit, an adaptive impedance matching network, a piezoelectric MEMS ultrasonic transducer, an active damping network, a preamplifier, a band-pass filter and a time gain controller; the high-voltage pulse driving circuit can greatly improve the emission sound pressure of the transducer and improve the measurement range; a controllable switch is designed at one end of the damping resistor, which can improve the emission efficiency and reduce the residual vibration, thereby reducing the measurement blind area; the adaptive impedance matching network is introduced, which can adjust the impedance inconsistent between different devices due to temperature and aging degree to the impedance matched with the ranging circuit, effectively improve the sensitivity and emission efficiency of the device, and the high sensitivity can improve the distance measurement precision of the ranging circuit.

The present invention discloses a preparation process of a piezoelectric MEMS chip, which includes the steps of: growing a piezoelectric layer on the front surface of a substrate; etching the piezoelectric layer to pattern the piezoelectric layer; growing a mask layer on the surface of the piezoelectric layer away from the substrate, etching the mask layer to pattern the mask layer; etching the back surface of the substrate to form a back cavity; etching the front surface of the substrate to pattern the front surface of the substrate; and stripping the mask layer. Compared with the traditional process, the preparation process of the piezoelectric MEMS chip of the present invention adds a mask layer, which increases the stability of the fragile structure of the piezoelectric MEMS chip through the mask layer, prevents fracture during etching, and improves the yield rate; at the same time, when stripping the mask layer, the material of the mucous layer is Si3N4, and when the mucous layer is formed in an environment of high temperature and large stress, the mask layer is naturally stripped to form the final piezoelectric MEMS chip.

The invention relates to the technical field of semiconductor technologies, in particular to a laminated piezoelectric MEMS structure and a preparation method thereof.The structure comprises a substrate, the substrate is provided with a front face and a back face which are opposite, a piezoelectric layer grows on the back face of the substrate, a substrate is bonded to the surface, away from the substrate, of the piezoelectric layer, and a back cavity penetrates through the substrate; the back cavity provides a vibration space for the vibrating diaphragm of the piezoelectric layer; the preparation method comprises the following steps: preparing a substrate having a front surface and a back surface opposite to each other, and growing a piezoelectric layer on the back surface of the substrate; preparing a substrate, and penetrating through the substrate to form a back cavity; the substrate is bonded to the surface, away from the substrate, of the piezoelectric layer, the back cavity is used for providing a vibration space for a vibrating diaphragm of the piezoelectric layer, the piezoelectric layer is grown through the glass substrate, the substrate serves as the substrate, the substrate can be directly and electrically connected with the first electrode and the second electrode respectively, additional packaging steps are not needed, and cost is saved.

The invention discloses a nested array piezoelectric MEMS loudspeaker, which is formed by arranging, nesting and combining a plurality of piezoelectric MEMS loudspeaker units together, a unit vibrating diaphragm is composed of a central vibrating diaphragm and extended rectangular vibrating diaphragms, the four edges of the central vibrating diaphragm are respectively provided with one extended rectangular vibrating diaphragm, the outer edges of the extended rectangular vibrating diaphragms are connected with a supporting base, and the supporting base is connected with the piezoelectric MEMS loudspeaker units. The actuator units are mutually nested and arranged through partially extending diaphragm structures, and in order to avoid crosstalk, the actuator units are mutually isolated through supporting substrates and air gaps. The array actuator has the beneficial effects that the actuator unit adopts a cross-shaped vibrating diaphragm design, so that the effective vibration area and out-of-plane displacement are improved, and the sound pressure level output of each part of array actuator unit under the fixed substrate size is improved; by modulating the difference of excitation signal phases of each part of array units under different voltages and different frequencies and coordinating with the vibration synthesis design realized by combining the array units, the programmable application requirements of the enhanced hearing aid can be met.

Various embodiments of the present disclosure are directed to a normally open piezoelectric MEMS (microelectromechanical system) device. A cantilever has a first end disposed over and bonded to a substrate and a second end opposite the first end and disposed over an actuator cavity. A piezoelectric actuator is disposed on the cantilever. A valve vane is bonded to the second end of the cantilever and is also disposed over a valve cavity laterally adjacent to the actuator cavity. The cantilever bends downward from the first end to the second end such that the valve vane is tilted and the valve cavity is opened. Upon release of the piezoelectric actuator, the cantilever bends upward to close the valve cavity.

The invention provides a cantilever beam type piezoelectric MEMS device and a preparation method thereof, and relates to the technical field of semiconductors. The cantilever beam type piezoelectric MEMS device comprises a limiting structure, the limiting structure is provided with a first cavity and a second cavity, and the outer contour of the orthographic projection of the first cavity on the second cavity is located in the side wall of the second cavity; a part of area of the cantilever beam is fixedly connected with the limiting structure, and the other part of area of the cantilever beam is arranged above the first cavity and the second cavity; the limiting structure forms a limiting area which can abut against the bent cantilever beam at the junction of the first cavity and the second cavity, and the minimum vertical distance between the limiting area and the side wall of the second cavity is two times or more than two times of the minimum vertical distance between the limiting area and the surface of the cantilever beam. According to the cantilever beam type piezoelectric MEMS device, the stress limit of the cantilever beam can be increased, and the cantilever beam type piezoelectric MEMS device has better impact resistance.

The invention discloses a piezoelectric MEMS sound wave emission unit with broadband response and an MEMS device, and belongs to the technical field of micro electro mechanical systems. According to the piezoelectric MEMS sound wave emission unit, a composite design scheme of an annular piezoelectric driving structure and a high Young modulus film is adopted, and collaborative improvement of broadband and high sound pressure output is realized by optimizing a vibration coupling mechanism; the overall structural design is compatible with a standard MEMS (Micro Electro Mechanical System) process, and the working bandwidth and the sound pressure output performance are remarkably improved while the miniaturization of the device is maintained. The technical scheme is particularly suitable for the professional fields of ultrasonic detection / imaging, piezoelectric MEMS loudspeakers and the like, and a new technical path is provided for the development of high-performance piezoelectric micromechanical sound wave emission units.

According to an example aspect of the present invention, a method for manufacturing a piezoelectric MEMS transducer (1) is presented, the method comprising forming at least one cantilever (10) from a silicon-on-insulator (SOI) wafer, where the at least one cantilever (10) comprises a first sidewall, a second sidewall substantially parallel to the first sidewall, an aluminum nitride (AlN) layer (40) and a top electrode (50), and where the at least one cantilever (10) comprises a second sidewall substantially parallel to the first sidewall, the second sidewall, the AlN layer (40) and the top electrode (50) are electrically connected to each other. The top electrode (50) is connected to at least the first sidewall and / or the second sidewall via an AlN layer (40) therebetween.

The invention discloses a resonant piezoelectric MEMS microphone with a high signal-to-noise ratio and application thereof, and belongs to the technical field of MEMS acoustic sensors. According to the resonant piezoelectric MEMS microphone, the suspended annular-film composite structure with the two ends symmetrically and fixedly supported is adopted, the high Young modulus film is sensitive to tiny stress change caused by sound waves, the rigid boundary is restrained through the film, vibration caused by the sound waves is more efficiently transmitted to the annular piezoelectric structure, the energy loss of the sound waves can be effectively reduced, and the reliability of the microphone is improved. And the sensitivity of the resonant microphone is obviously improved. Besides, the suspended annular-film composite structure with two ends symmetrically and fixedly supported overcomes the problems of low Q value and large energy loss of a traditional resonant microphone (such as a cantilever beam structure), so that the resonant peak is sharper, and the microphone is more sensitive to tiny resonant frequency deviation caused by sound waves. Moreover, the larger the Q value is, the smaller the noise is, and compared with a traditional capacitive microphone and a traditional piezoelectric microphone, the SNR can be greatly improved in a low-frequency band.

The invention discloses a high-power low-intensity noise semiconductor laser packaging structure, which structurally comprises a heat management module, a heat sink base, a laser chip, a chip base, an optical coupling module, a packaging shell and an intensity noise processing module, wherein the laser chip, the chip base and the optical coupling module are positioned above the heat sink base; the intensity noise processing module is positioned in a non-light-path area of the inner side wall of the packaging shell; the laser chip is used as a laser emission core to provide initial laser; the optical coupling module performs beam shaping, feedback control and output coupling on laser emitted by the laser chip; the intensity noise processing module comprises a piezoelectric MEMS sensor and a photonic crystal electrical filter and is used for performing feedback suppression on intensity noise; and the thermal management module performs temperature control on the laser chip and the optical coupling module. Through the synergistic effect of controllable optical feedback of the optical coupling module and precise temperature control of the temperature controller, the semiconductor laser light source still keeps extremely low intensity noise under the high-power output condition, and good repeatability and high reliability are achieved.

Provided is a piezoelectric MEMS acoustic sensor, comprising a substrate, an inner electrode area, and an outer electrode area; the outer electrode area is located at the periphery of the inner electrode area; a lower support layer is provided on the top of the substrate, the inner electrode area and the outer electrode area are located on the lower support layer, and an upper support layer made of silicon-based material is provided on the top surfaces of the inner electrode area and the outer electrode area. The piezoelectric MEMS acoustic sensor has high sensitivity, strong resistance to hydrostatic pressure, and satisfies application requirements of different pressure resistance and operating water depth.

A method of making an acoustic sensor (e.g., for use in a piezoelectric MEMS microphone) includes forming or providing a mold having one or more grooves in a top surface of the mold that extend in a direction of the length of the mold to a distal end of the mold. The method also includes forming or depositing a structure having one or more piezoelectric layers over the top surface of the mold to define a beam, the distal portion of the beam having a corrugated section including one or more grooves that correspond to the grooves of the mold. The method also includes forming a gap in the structure to define two beams separated by the gap, and releasing the structure from the mold to form one or more cantilever beams that increases an acoustic resistance of the gap between sensors.

The invention provides a three-dimensional positioning piezoelectric MEMS microphone and a preparation method thereof. Comprising a substrate which is provided with a back cavity; the back cavity comprises a first back cavity and a second back cavity which are arranged in the direction perpendicular to the substrate; the first back cavity and the second back cavity are correspondingly arranged and are communicated with each other; the piezoelectric vibrating diaphragm structure is arranged corresponding to the back cavity; the piezoelectric diaphragm structure comprises a frame, an X-direction high-sensitivity sensing cantilever beam combination and a Y-direction high-sensitivity sensing cantilever beam combination; the X-direction high-sensitivity sensing cantilever beam combination comprises one or more pairs of main cantilever beams, and each pair of main cantilever beams is fixed to the frame through a main supporting beam. Each main cantilever beam is provided with a cantilever beam groove, the Y-direction high-sensitivity sensing cantilever beam combination is arranged at the cantilever beam groove of each main cantilever beam, the Y-direction high-sensitivity sensing cantilever beam combination comprises one or more pairs of secondary cantilever beams, and each pair of secondary cantilever beams are fixed on the main cantilever beams through secondary supporting beams.