The present disclosure relates to a Bulk Acoustic Wave (BAW) resonator, which includes a bottom electrode, a top electrode structure, and a multilayer transduction structure sandwiched therebetween. Herein, the multilayer transduction structure is composed of multiple transduction layers, at least one of which is formed of a ferroelectric material with a box-shape polarization-electric field curve. Each transduction layer includes a transduction border (BO) portion positioned at a periphery of a corresponding transduction layer and a transduction central portion surrounded by the transduction BO portion. A combination of all transduction BO portions forms a transduction BO section of the multilayer transduction structure, and a combination of all transduction central portions forms a transduction central section of the multilayer transduction structure. An electromechanical coupling coefficient of the transduction BO section is less than an electromechanical coupling coefficient of the transduction central section.

An acoustic wave device has a multilayer piezoelectric substrate (MPS) structure and a multilayer interdigital transducer electrode (IDT). The multilayer piezoelectric substrate includes a piezoelectric layer over a support substrate. An additional (functional) layer can optionally be interposed between the piezoelectric layer and the support substrate, which can facilitate bonding between these layers and provide temperature compensation. The multilayer IDT is disposed over the piezoelectric layer and includes a first layer of a first material with higher density and a second layer of a different material with lower density. The interdigital transducer electrode also includes (mass loading) strips disposed over (e.g., adjacent, in contact with) the second layer, which advantageously facilitate suppression of transverse mode.

A microwave dielectric component (100) comprises a microwave dielectric substrate (101) and a metal layer, the metal layer being bonded to a surface of the microwave dielectric substrate (101). The metal layer comprises a conductive seed layer and a metal thickening layer (105). The conductive seed layer comprises an ion implantation layer (103) implanted into the surface of the microwave dielectric substrate (101) and a plasma deposition layer (104) adhered on the ion implantation layer (103). The metal thickening layer (105) is adhered on the plasma deposition layer (104). A manufacturing method of the microwave dielectric component (100) is further disclosed.

An electroacoustic device includes, stacked in a direction a silicon-based substrate, a first electrode, a piezoelectric layer with the basis of a perovskite taken from among lithium niobate LiNbO3, lithium tantalum LiTaO3, or an Li(Nb,Ta)O3 alloy, on the first electrode, a second electrode disposed on the piezoelectric layer. Advantageously, the first electrode is made of a nitride-based electrically conductive refractory material, such as TiN, VN, TaN. The invention also relates to a method for producing such a device.

Techniques for improving Bulk Acoustic Wave (BAW) reflector and resonator structures are disclosed, including filters, oscillators and systems that may include such devices. A Bulk Acoustic Wave (BAW) resonator of this disclosure may comprise a substrate and an active piezoelectric resonant volume. The active piezoelectric resonant volume of the Bulk Acoustic Wave (BAW) resonator may have a main resonant frequency. The active piezoelectric resonant volume of the Bulk Acoustic Wave (BAW) resonator may comprise first and second piezoelectric layers having respective piezoelectric axis that substantially oppose one another. A first patterned layer may be disposed within the active piezoelectric volume. This may, but need not facilitate suppression of spurious modes. The main resonant frequency of the Bulk Acoustic Wave (BAW) resonator may be in a super high frequency (SHF) band. The main resonant frequency of the Bulk Acoustic Wave (BAW) resonator may be in an extremely high frequency (EHF) band.

A micro-electrical-mechanical system (MEMS) resonator device includes at least one functionalization material arranged over at least a central portion, but less than an entirety, of a top side electrode. For an active region exhibiting greatest sensitivity at a center point and reduced sensitivity along its periphery, omitting functionalization material over at least one peripheral portion of a resonator active region prevents analyte binding in regions of lowest sensitivity. The at least one functionalization material extends a maximum length in a range of from about 20% to about 95% of an active area length and extends a maximum width in a range of from about 50% to 100% of an active area width. Methods for fabricating MEMS resonator devices are also provided.

A resonator circuit device. This device can include a piezoelectric layer having a front-side electrode and a back-side electrode spatially configured on opposite sides of the piezoelectric layer. Each electrode has a connection region and a resonator region. Each electrode also includes a partial mass-loaded structure configured within a vicinity of its connection region. The front-side electrode and the back-side electrode are spatially configured in an anti-symmetrical manner with the resonator regions of both electrodes at least partially overlapping and the first and second connection regions on opposing sides. This configuration provides a symmetric acoustic impedance profile for improved Q factor and can reduce the issues of misalignment or unbalanced boundary conditions associated with conventional single mass-loaded perimeter configurations.

The piezoelectric vibration plate includes a piezoelectric substrate, a first driving electrode and a second driving electrode formed on main surfaces on both sides of the piezoelectric substrate, and a first mounting terminal and a second mounting terminal respectively connected to the first driving electrode and the second driving electrode. The first and second mounting terminals each have a metal film for mounting purpose formed on the piezoelectric substrate and a metal film for driving purpose formed on the metal film for mounting purpose. The metal films for mounting purpose each include a solder-resistant metal film. The metal films for driving purpose are formed in continuity with the first and second driving electrodes and constitute the first and second driving electrodes.

A method for manufacturing an acoustic device includes providing a substrate, providing a bottom electrode over the substrate, providing a sacrificial layer on the bottom electrode, patterning the bottom electrode and the sacrificial layer, polishing the sacrificial layer such that a portion of the sacrificial layer remains on the bottom electrode, and removing the remaining portion of the sacrificial layer via a cleaning process such that a surface roughness of the bottom electrode is maintained. By performing the polishing such that a portion of the sacrificial layer remains on the bottom electrode and subsequently removing that portion of the sacrificial layer via a cleaning process that maintains the surface roughness of the bottom electrode, the subsequent growth of a piezoelectric layer on the bottom electrode can be substantially improved.

A vibration element includes: a base; a first arm continuous with the base; a second arm that is continuous with the base and is adjacent to the first arm; a first electrode disposed on the first arm, the second arm, and the base; a first piezoelectric layer that has a first polarity and that is disposed on the first electrode on the first arm; a second piezoelectric layer that has a second polarity different from the first polarity and that is disposed on the first electrode on the second arm; an insulating layer disposed on the first electrode on the base; and a second electrode disposed on the first piezoelectric layer, the second piezoelectric layer, and the insulating layer.