A process for fabricating a component includes an operation of transferring at least one layer of one or more piezoelectric or pyroelectric or ferroelectric materials forming part of a donor substrate to a final substrate, the process comprising a prior step of joining the layer to a temporary substrate via production of a fragile separating region between the donor substrate of single-crystal piezoelectric or pyroelectric or ferroelectric material and the temporary substrate, the region comprising at least two layers of different materials in order to ensure two compounds apt to generate an interdiffusion of one or more constituent elements of at least one of the two compounds make contact, the fragile region allowing the temporary substrate to be separated.

Acoustic resonator devices and methods are disclosed. An acoustic resonator device includes a piezoelectric plate having opposed front and back surfaces. A first electrode and a second electrode are formed on the front surface of the piezoelectric plate, the first and second electrodes and the piezoelectric plate configured such that a radio frequency signal applied between the first and second electrodes excites a shear primary acoustic mode in the piezoelectric plate. The first electrode and the second electrode have trapezoidal cross-sectional shapes. A sidewall angle of at least one side surface of the first electrode and a sidewall angle of at least one side surface of the second electrode are greater than or equal to 70 degrees and less than or equal to 110 degrees.

A method for fabricating a multi-layer resonator assembly includes sequentially fabricating a plurality of vertically-stacked resonator layers including, for each resonator layer of the plurality of resonator layers, depositing a dielectric layer, forming at least one film bulk acoustic resonator (FBAR) cavity in the deposited dielectric layer, filling each FBAR cavity of the at least one FBAR cavity with a sacrificial material block, and depositing a FBAR material stack over the at least one FBAR cavity. The deposited FBAR material stack is in contact with the sacrificial material block and the dielectric layer. The method further includes removing the sacrificial material block from the at least one FBAR cavity for each resonator layer of the plurality of resonator layers subsequent to sequentially fabricating the plurality of resonator layers.

A film bulk acoustic resonator and a manufacturing method therefor are provided. The film bulk acoustic resonator includes: a substrate, and a lower electrode, a piezoelectric layer, electrode frame layers and an upper electrode sequentially stacked on the substrate; wherein a cavity is formed between the substrate and the lower electrode, a Q-increasing structure is formed by the lower electrode in a vertical projection range of the cavity, and a first air wing and a first air bridge are formed between the upper electrode and the piezoelectric layer.

An acoustic filter device includes first and second series resonators and at least one shunt resonator, each shunt resonator electrically coupled to the first series resonator or the second series resonator. Each of the first and second series resonators includes respective first and second sub-resonators electrically connected in series, The first sub-resonators of the first and second series resonators are acoustically coupled along a first shared acoustic track. The second sub-resonators of the first and second series resonators are acoustically coupled along a second shared acoustic track.

A method for fabricating a film bulk acoustic resonator (FBAR) structure includes: obtaining a wafer, at least a portion of the wafer is made of a piezoelectric material; forming a bottom electrode layer on the wafer; patterning the bottom electrode layer to form a bottom electrode; forming a sacrificial island on the bottom electrode; bonding a bottom cap wafer onto the bottom electrode; processing the wafer to form a piezoelectric layer; forming a top electrode layer on the piezoelectric layer; patterning the top electrode layer to form a top electrode; and removing the sacrificial island to form a cavity.

Techniques for improving Bulk Acoustic Wave (BAW) reflector and 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 substantially opposes the first piezoelectric axis orientation of the first layer of piezoelectric material. A top acoustic reflector electrode may include a first pair of top metal electrode layers electrically and acoustically coupled with the first and second layer of piezoelectric material to excite the piezoelectrically excitable resonance mode at a resonant frequency of the BAW resonator. The resonant frequency of the BAW resonator may be in a super high frequency band or an extremely high frequency band.

An acoustic resonator that has a first electrode with a first planar portion. A second electrode having a second planar portion is disposed parallel to the first planar portion. This second electrode has a bifurcated end that defines a gap. A piezoelectric layer is disposed between and contacts both the first planar portion and the second planar portion. Also contacting the piezoelectric layer is the bifurcated end of the second electrode. The gap is formed in the periphery of each resonator within a filter. It is formed in the top electrode, that is typically formed of molybdenum, but could be formed from other metals as well. Unlike a gap between a top electrode and piezoelectric material, the gap recited herein is entirely within the second electrode. This structure is compatible with an inner passivation layer that enables a single crystal piezoelectric layer and a larger bottom electrode.

A bulk acoustic wave (BAW) resonator includes a piezoelectric layer, a first electrode layer disposed on a first side of the piezoelectric layer and including a first electrode and an additional electrode electrically isolated from each other, a second electrode layer disposed on a second side of the piezoelectric layer and including a second electrode, one or more conductive pads disposed on the second side of the piezoelectric layer and at least including an interconnection pad electrically connected to the second electrode and the additional electrode, a carrier structure disposed on the first side of the piezoelectric layer, a cover structure disposed on the second side of the piezoelectric layer and including a cover bonding layer and a cover substrate. A first cavity is disposed between the carrier structure and the piezoelectric layer. A second cavity is disposed between the cover structure and the piezoelectric layer.

A method for manufacturing a film bulk acoustic resonance device is disclosed. The proposed method, wherein the device has a specific resonant frequency, includes: providing a substrate having a recess, wherein the recess has a height; configuring a first piezoelectric material layer on the substrate, and causing the recess to form an air gap; configuring a lower electrode on the first piezoelectric material layer; when the height is in a first range, causing a resonant frequency of the film bulk acoustic resonance device versus the height to have a first slope; when the height is in a second range, causing the resonant frequency versus the height to have a second slope; and causing the first slope to be smaller than the second slope.