An array of piezoelectric micromachined ultrasound transducers (PMUTs) has a layer of piezoelectric material that requires poling during fabrication in order to properly align the piezoelectric dipoles to create a desired ultrasonic signal. The PMUT may have an interconnected set of lower electrodes that are fabricated between a processing layer of the PMUT and the piezoelectric layer. An upper electrode is fabricated overlaying the piezoelectric layer, and a poling voltage is applied between the upper electrode and the interconnected set of lower electrodes. After poling is complete, portions of the interconnected set of lower electrodes are removed to permanently isolate permanent lower electrodes from each other.

Acoustic resonator devices and methods are disclosed. An acoustic resonator device includes a substrate having a front surface and a cavity, a perimeter of the cavity defined by a lateral etch-stop comprising etch-stop material. A back surface of a single-crystal piezoelectric plate is attached to the front surface of the substrate except for a portion of the piezoelectric plate that forms a diaphragm that spans the cavity. An interdigital transducer (IDT) is formed on the front surface of the single-crystal piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. The piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the diaphragm.

Acoustic resonator devices and methods are disclosed. An acoustic resonator device includes a substrate having a front surface and a cavity, a perimeter of the cavity defined by a lateral etch-stop comprising etch-stop material. A back surface of a single-crystal piezoelectric plate is attached to the front surface of the substrate except for a portion of the piezoelectric plate that forms a diaphragm that spans the cavity. An interdigital transducer (IDT) is formed on the front surface of the single-crystal piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. The piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the diaphragm.

A semiconductor device may include: a substrate wafer, a bonding layer at least partially covering a front surface of the substrate wafer, a plurality of silicon pillars bonded to the front surface of the substrate wafer by the bonding layer, a single-crystal piezoelectric film having a first surface and an opposing second surface, a top electrode arranged adjacent to the first surface of the single-crystal piezoelectric film, and a bottom electrode arranged adjacent to the second surface of the single-crystal piezoelectric film. The single-crystal piezoelectric film may be supported by the plurality of silicon pillars such that the second surface of the piezoelectric film and the front surface of the substrate wafer enclose a cavity therebetween.

A movable piezo element and to a method for producing the element are provided. The movable piezo element may have a structured substrate, in which an intermediate layer is arranged between a first substrate layer and a second substrate layer. The element may also have a first electrode layer. The element may also have a second electrode layer arranged on the ferroelectric, piezoelectric, or flexoelectric layer. The second substrate layer may be structured such that at least one bar of the second substrate layer is formed. The bar may be clamped on one side and may be physically spaced from the first substrate layer. A surface of the bar facing away from the first substrate layer, and/or a lateral surface of the bar, may be at least partly covered by another layer.

[Object] To provide a technology such as a piezoelectric coil having higher energy conversion efficiency.

[Solving Means] A piezoelectric coil according to the present technology includes a coil-like core material and a plurality of band-like piezoelectric materials. The plurality of piezoelectric materials is helically wound around the core material so as to be alternately arranged along the core material.

A method of fabricating and controlling a thick-film transducer array for steering and focusing ultrasonic waves within a substrate volume is provided. A ceramic film composition can be coated on a substrate volume in one or more layers. The ceramic film can be masked with a plastic sheet out of which an electrode pattern is cut. Conductive electrode material can be applied to the pattern to create a transducer array that can be polarized with an applied electric field. A method of controlling a thick-film transducer array comprises exciting one or more array elements to generate a wavefield in a substrate volume, the wavefield can be reflected by features within the substrate volume, one or more array elements can receive reflected wavefield signals, and images of the insonified substrate volume can be generated.

A crystal oscillator includes an oscillating substrate, a hollow frame, a first electrode, and a second electrode. The oscillating substrate includes a main oscillating region and a thinned region that has a thickness smaller than that of the main oscillating region. The first and second electrodes are disposed on a first surface of the oscillating substrate and a second surface opposite to the first surface, respectively. The hollow frame is disposed on the second surface. The second electrode includes a second electrode portion that has at least one opening in positional correspondence with the thinned region. A method for making the crystal oscillator is also provided herein.

A crystal oscillator includes an oscillating substrate, a hollow frame, a first electrode, and a second electrode. The oscillating substrate includes a main oscillating region and a thinned region that has a thickness smaller than that of the main oscillating region. The first and second electrodes are disposed on a first surface of the oscillating substrate and a second surface opposite to the first surface, respectively. The hollow frame is disposed on the second surface. The second electrode includes a second electrode portion that has at least one opening in positional correspondence with the thinned region. A method for making the crystal oscillator is also provided herein.

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.