An acoustic resonator device includes a piezoelectric plate attached to a substrate. A portion of the piezoelectric plate forms a diaphragm suspended over a cavity in the substrate. A first conductor level includes first and second interdigital transducer (IDT) first-level busbars disposed along opposing sides of the diaphragm, and first and second sets of IDT fingers extending from the first and second busbars, respectively, wherein the first and second sets of IDT fingers are interleaved and disposed on the diaphragm. A second conductor level includes first and second second-level busbars that overlap at least a portion of the first and second busbars, respectively.

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.

An RF integrated circuit device can includes a substrate and a High Electron Mobility Transistor (HEMT) device on the substrate including a ScAlN layer configured to provide a buffer layer of the HEMT device to confine formation of a 2DEG channel region of the HEMT device. An RF piezoelectric resonator device can be on the substrate including the ScAlN layer sandwiched between a top electrode and a bottom electrode of the RF piezoelectric resonator device to provide a piezoelectric resonator for the RF piezoelectric resonator device.

A method of manufacture for an acoustic resonator or filter device. In an example, the present method can include forming metal electrodes with different geometric areas and profile shapes coupled to a piezoelectric layer overlying a substrate. These metal electrodes can also be formed within cavities of the piezoelectric layer or the substrate with varying geometric areas. Combined with specific dimensional ratios and ion implantations, such techniques can increase device performance metrics. In an example, the present method can include forming various types of perimeter structures surrounding the metal electrodes, which can be on top or bottom of the piezoelectric layer. These perimeter structures can use various combinations of modifications to shape, material, and continuity. These perimeter structures can also be combined with sandbar structures, piezoelectric layer cavities, the geometric variations previously discussed to improve device performance metrics.

An RF filter system includes a plurality of bulk acoustic wave resonators arranged in a circuit having serial and parallel shunt configurations of resonators. Each resonator having a reflector, a support member including a surface, a first electrode including tungsten, overlying the reflector, a piezoelectric film including crystalline aluminum scandium nitride overlapping the first electrode, a second electrode including tungsten overlapping the piezoelectric film and the first electrode, and a passivation layer including silicon nitride overlying the second electrode. Portions of the support member surface of at least one resonator define a cavity region having a portion of the first electrode of the at least one resonator is located within the cavity region. The pass band circuit response has a bandwidth corresponding to a thickness of at least one of the first electrode, piezoelectric film, second electrode, and passivation layer. The system can include single crystal or polycrystalline BAW resonators.

An RF circuit device using modified lattice, lattice, and ladder circuit topologies. The devices can include four resonator devices and four shunt resonator devices. In the ladder topology, the resonator devices are connected in series from an input port to an output port while shunt resonator devices are coupled the nodes between the resonator devices. In the lattice topology, a top and a bottom serial configurations each includes a pair of resonator devices that are coupled to differential input and output ports. A pair of shunt resonators is cross-coupled between each pair of a top serial configuration resonator and a bottom serial configuration resonator. The modified lattice topology adds baluns or inductor devices between top and bottom nodes of the top and bottom serial configurations of the lattice configuration. These topologies may be applied using single crystal or polycrystalline bulk acoustic wave (BAW) resonators.

The present disclosure provides a film bulk acoustic resonator and a method for fabricating the film bulk acoustic resonator. The resonator includes a carrier substrate; a support layer bonded on the carrier substrate, where the support layer encloses a first cavity exposing the carrier substrate; a piezoelectric stacked structure covering the first cavity, where the piezoelectric stacked structure includes a first electrode, a piezoelectric layer, and a second electrode which are stacked sequentially from a bottom to a top; and protrusions disposed at a boundary of an effective resonance region, where the protrusions are disposed on an upper surface or a lower surface of the piezoelectric stacked structure; or a part of the protrusions is disposed on the upper surface of the piezoelectric stacked structure, and another part of the protrusions is disposed on the lower surface of the piezoelectric stacked structure.

Acoustic resonators and filter devices. An acoustic resonator includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces. The back surface is attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A conductor pattern formed is formed on the front surface of the piezoelectric plate, including an interdigital transducer (IDT) with interleaved fingers of the IDT on the diaphragm. The substrate and the piezoelectric plate are the same material.

A radio frequency filter includes at least a first sub-filter and a second sub-filter connected in parallel between a first port and a second port. Each of the sub-filters has a piezoelectric plate having front and back surfaces, the back surface attached to a substrate, and portions of the piezoelectric plate forming diaphragms spanning respective cavities in the substrate. A conductor pattern is formed on the front surface of the plate, the conductor pattern includes interdigital transducers (IDTs) of a respective plurality of resonators, with interleaved fingers of each IDT disposed on a respective diaphragm of the plurality of diaphragms. A thickness of the portions of the piezoelectric plate of the first sub-filter is different from a thickness of the portions of the piezoelectric plate of the second sub-filter.

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.