An acoustic resonator device is provided that includes a wafer having a wafer surface and a wafer conductor pattern on the wafer surface; a piezoelectric layer having front and back surfaces, a portion of the piezoelectric layer being over a cavity between the wafer and the piezoelectric layer, and the wafer conductor pattern; a device conductor pattern including a first metal layer including an interdigital transducer on the front surface of the piezoelectric layer and facing the wafer, and a second metal layer attached to a portion of the device conductor pattern to provide an electrical connection between the IDT and the wafer conductor pattern. The second metal layer is bonded to the wafer conductor pattern and the piezoelectric layer comprises openings extending therethrough.

An acoustic resonator device is formed using a wafer-to-wafer bonding process by etching recesses into a first surface of a piezoelectric substrate, a depth of the recesses greater than a target piezoelectric membrane thickness; then wafer-to-wafer bonding the first surface of the piezoelectric substrate to a handle wafer using a releasable bonding method. The piezoelectric substrate is then thinned to the target piezoelectric membrane thickness to form a piezoelectric plate and at least one conductor pattern is formed on the thinned piezoelectric plate. The side of the thinned piezoelectric plate having the conductor pattern is bonded to a carrier wafer using a metal-to-metal wafer bonding process and the handle wafer is removed.

Techniques for improving acoustic wave device structures are disclosed, including filters and systems that may include such devices. An apparatus may comprise a first electrical filter including an acoustic wave device. The first electrical may having a first filter band in a Super High Frequency (SHF) band or an Extremely High Frequency (EHF) band to facilitate compliance with a regulatory requirement or a standards setting organization specification. For example, the first electrical filter may comprise a notch filter having a notch band overlapping at least a portion of an Earth Exploration Satellite Service (EESS) band to facilitate compliance with a regulatory requirement or the standards setting organization specification for the Earth Exploration Satellite Service (EESS) band.

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

In one example, an apparatus comprises an acoustic resonator, the acoustic resonator including: an electrode; and a piezoelectric layer on the electrode, in which the electrode covers entirely a surface of the piezoelectric layer, and the piezoelectric layer has a convex portion with a non-uniform thickness.

The present disclosure provides a bulk acoustic wave resonator, a method for manufacturing a bulk acoustic wave resonator and an electronic device, and belongs to the field of communication technology. The bulk acoustic wave resonator of the present disclosure includes: a first base substrate, a first electrode, a piezoelectric layer, and a second electrode; the first electrode is on the first base substrate, the second electrode is on a side of the first electrode away from the first base substrate, the piezoelectric layer is between the first electrode and the second electrode; and orthographic projections of any two of the first electrode, the piezoelectric layer and the second electrode on the first base substrate at least partially overlap with each other; wherein an acoustic velocity of a material of the piezoelectric layer is no less than 18000 m/s.

The present disclosure provides a bulk acoustic wave resonator and an electronic device, and belongs to the field of communication technology. The bulk acoustic wave resonator of the present disclosure includes: a base substrate, a first electrode, a piezoelectric layer, and a second electrode; the first electrode is on the base substrate, the second electrode is on a side of the first electrode away from the base substrate, the piezoelectric layer is between the first electrode and the second electrode; and orthographic projections of any two of the first electrode, the piezoelectric layer and the second electrode on the base substrate at least partially overlap with each other; wherein the bulk acoustic wave resonator further includes: a first heat conduction layer on a side of the first electrode close to the base substrate.

A cavity structure of a bulk acoustic resonator and a manufacturing process. The cavity structure comprises a substrate and a cavity formed on the substrate, a support layer is arranged on the substrate to form the cavity in a surrounding manner, a release channel in communication with the cavity is formed above the substrate in a same layer with the cavity, and the release channel extends, in parallel to the substrate, in a peripheral area of the cavity. There is no need to manufacture a release hole, which simplifies the manufacturing process of the resonator, thereby avoiding weakening the performance of the resonator due to damage to the structure of the piezoelectric layer around the electrode layer when manufacturing the release hole.

A bulk acoustic wave resonant structure and a preparation method therefor, and an acoustic wave device are provided. The bulk acoustic wave resonant structure includes: a substrate; a reflection structure, a first electrode, a piezoelectric layer and a second electrode, which are successively located on the substrate, wherein the first electrode comprises a first sub-electrode located in a first region and a second sub-electrode located in a second region other than the first region, and the piezoelectric layer respectively comes into direct contact with the first sub-electrode and the second electrode in the first region; and a first gap, which is located between the piezoelectric layer and the second sub-electrode, wherein an orthographic projection of the first gap on the substrate surrounds the first region.

A bulk acoustic wave (BAW) resonator includes a bottom substrate, a piezoelectric layer disposed above the bottom substrate, a cap wafer disposed above the piezoelectric layer, a top electrode disposed on the piezoelectric layer, a bottom electrode disposed below the piezoelectric layer, a first pad metal layer disposed on and electrically connected to the top electrode. a second pad metal layer disposed on and electrically connected to the bottom electrode, a top bonding layer disposed below the cap wafer, for bonding the cap wafer with the piezoelectric layer; and a bond contacting layer disposed between the top bonding layer and each one of the first pad metal layer and the second pad metal layer.