Acoustic resonator devices, filter devices, and methods of fabrication. A resonator device includes a piezoelectric plate having a front surface and a back surface opposite the front surface, a back-side conductor pattern formed on the back surface, and a first front-side conductor pattern and a second front-side conductor pattern formed on respective portions of the front surface opposite the back-side conductor pattern. A portion of the piezoelectric plate between the first front-side conductor pattern and the back-side conductor pattern forms a first resonator and a portion of the piezoelectric plate between the second front-side conductor pattern and the back-side conductor pattern forms a second resonator.

The disclosure provides a packaging structure and method of an acoustic device, relating the technical field of semiconductors, including: a substrate and a piezoelectric stack structure located on the substrate, a first organic material layer is disposed on the piezoelectric stack structure, a second organic material layer is disposed on the first organic material layer, the first organic material layer includes a first supporting part and a second supporting part, the second supporting part forms a first acoustic reflection structure, when being transmitted to the first acoustic reflection structure, acoustic waves can be reflected back to the effective area, so that the loss of the acoustic waves is reduced, and the performance of the acoustic device is improved. The first supporting part is matched with the second organic material layer to form a second acoustic reflection structure, so that when part of acoustic waves are not reflected back by the first acoustic reflection structure and are transmitted to the second acoustic reflection structure, the acoustic waves can be reflected back to the effective area, so that the loss of the acoustic waves is further reduced, and the performance of the acoustic device is improved.

Aspects of this disclosure relate to a bulk acoustic wave device with a floating raised frame structure. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a floating raised frame structure positioned on a same side of the piezoelectric layer as the first electrode and spaced apart from the first electrode. The floating raised frame structure is at a floating potential. The bulk acoustic wave device can suppress a raised frame mode. Related methods, filters, multiplexers, radio frequency front ends, radio frequency modules, and wireless communication devices are disclosed.

Acoustic sensor devices and sensor systems are disclosed. An acoustic sensor device includes a piezoelectric plate having a front surface and a back surface. A floating back-side conductor pattern is formed on the back surface. A first and second front-side conductor patterns are formed on a portion of the front surface opposite the back-side conductor pattern. A sensing layer is formed over all or a portion of the floating back-side conductor pattern.

An acoustic wave device assembly is disclosed. The acoustic wave device assembly can include a first acoustic wave device that includes a first substrate, a first piezoelectric layer, a first solid acoustic mirror that is disposed between the first substrate and the first piezoelectric layer, and a first interdigital transducer electrode that is in contact with the first piezoelectric layer. The acoustic wave device assembly can include a second acoustic wave device that includes a second substrate, a second piezoelectric layer, a second solid acoustic mirror that is disposed between the second substrate and the second piezoelectric layer, a second interdigital transducer electrode that is in contact with the second piezoelectric layer, and a third solid acoustic mirror over the second interdigital transducer electrode. The first acoustic wave device and the second acoustic wave device being stacked on one another. The acoustic wave device assembly can include a spacer assembly that is disposed over the first piezoelectric layer.

An acoustic wave device assembly is disclosed. The acoustic wave device assembly can include a first acoustic wave device that includes a first substrate, a first piezoelectric layer, a first solid acoustic mirror that is disposed between the first substrate and the first piezoelectric layer, and a first interdigital transducer electrode that is embedded in the piezoelectric layer. The acoustic wave device assembly can include a second acoustic wave device that includes a second substrate, a second piezoelectric layer, a second solid acoustic mirror that is disposed between the second substrate and the second piezoelectric layer, and a second interdigital transducer electrode that is in contact with the second piezoelectric layer. The second acoustic wave device is stacked over the first acoustic wave device. The first acoustic wave device and the second acoustic wave device are spaced by a spacer assembly such that a cavity is formed between the first acoustic wave device and the second acoustic wave device.

An acoustic wave device assembly is disclosed. The acoustic wave device assembly can include a first interdigital transducer electrode that is in contact with a first piezoelectric layer, and a second interdigital transducer electrode that is in contact with a second piezoelectric layer. The acoustic wave device assembly can include an acoustic mirror structure that is positioned between the first interdigital transducer electrode and the second interdigital transducer electrode. The acoustic mirror structure has a first portion that is configured to confine acoustic energy of a first acoustic wave generated by the first interdigital transducer electrode, and a second portion that is configured to confine acoustic energy of a second acoustic wave generated by the second interdigital transducer electrode.

A stacked acoustic wave device assembly is disclosed. The stacked acoustic wave device assembly can include a first acoustic wave device that includes a first substrate, a first piezoelectric layer, a first solid acoustic mirror that is disposed between the first substrate and the first piezoelectric layer, and a first interdigital transducer electrode that is in contact with the first piezoelectric layer. The stacked acoustic wave device assembly can include a second acoustic wave device that includes a second substrate, a second piezoelectric layer, a second solid acoustic mirror that is disposed between the second substrate and the second piezoelectric layer, and a second interdigital transducer electrode that is in contact with the second piezoelectric layer. The second acoustic wave device is stacked over the first acoustic wave device. The first acoustic wave device and the second acoustic wave device are spaced by a spacer assembly such that a cavity is formed between the first acoustic wave device and the second acoustic wave device.

Techniques for improving Bulk Acoustic Wave (BAW) resonator structures are disclosed, including filters, oscillators and systems that may include such devices. First and second layers of piezoelectric material may be acoustically coupled with one another to have a piezoelectrically excitable resonance mode. The first layer of piezoelectric material may have a first piezoelectric axis orientation, and the second layer of piezoelectric material may have a second piezoelectric axis orientation that opposes the first piezoelectric axis orientation of the first layer of piezoelectric material. A top acoustic reflector including a first pair of top metal electrode layers may be electrically and acoustically coupled with the first layer of piezoelectric material to excite the piezoelectrically excitable main resonance mode at a resonant frequency.

Acoustic resonators and filters are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate. A back surface of the piezoelectric plate is attached to the substrate except for a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A conductor pattern including an interdigital transducer (IDT) is formed on a front surface of the piezoelectric plate, interleaved fingers of the IDT disposed on the diaphragm. A front-side dielectric layer is formed on the front surface of the piezoelectric plate between, but not over, the IDT fingers. A back-side dielectric layer is formed on a back surface of the diaphragm. Thicknesses of the IDT fingers and the front-side dielectric layer are substantially equal. An acoustic impedance Zm of the IDT fingers and an acoustic impedance Zfd of the front-side dielectric layer satisfy the relationship 0.8Zm≤Zfd≤1.25Zm.