A structure, comprising an island comprising a III-N material. The island extends over a substrate and has a sloped sidewall. A cap comprising a III-N material extends laterally from a top surface and overhangs the sidewall of the island. A device, such as a transistor, light emitting diode, or resonator, may be formed within, or over, the cap.

Acoustic filters and methods are disclosed. A single-crystal piezoelectric is attached to a substrate, portions of the piezoelectric plate forming one or more diaphragms spanning respective cavities in the substrate. A conductor pattern is formed on the piezoelectric plate, the conductor pattern including a plurality of interdigital transducers (IDTs) of a plurality of resonators, interleaved fingers of each of the plurality of IDTs disposed on a respective diaphragm of the one or more diaphragms. A first frequency setting dielectric layer having a first thickness is disposed over the fingers of the IDTs of a first subset of the plurality of resonators. A second frequency setting dielectric layer having a second thickness greater than the first thickness is disposed over the fingers of the IDTs of a second subset of the plurality of resonators, wherein the first subset and the second subset are not identical.

Acoustic resonator devices and filters are disclosed. A piezoelectric plate is attached to a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A first conductor pattern is formed on a surface of the piezoelectric plate. The first conductor pattern includes interleaved fingers of an interdigital transducer disposed on the diaphragm, and a first plurality of contact pads. A second conductor pattern is formed on a surface of a base, the second conductor pattern including a second plurality of contact pads. Each pad of the first plurality of contact pads is directly bonded to a respective pad of the second plurality of contact pads. A ring-shaped seal is form between a perimeter of the piezoelectric plate and a perimeter of the base.

Acoustic resonator devices and filters are disclosed. An acoustic resonator includes a substrate having a surface and a single-crystal piezoelectric plate having parallel front and back surfaces, the back surface attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm that spans a cavity in the substrate. 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 IDT is configured to excite a primary acoustic mode in the diaphragm in response to a radio frequency signal applied to the IDT. A direction of acoustic energy flow of the primary acoustic mode is substantially orthogonal to the front and back surfaces of the diaphragm. The diaphragm is contiguous with the piezoelectric plate around at least 50% of a periphery of the diaphragm.

Acoustic resonator devices and filters are disclosed. A piezoelectric plate is attached to a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A first conductor pattern is formed on a surface of the piezoelectric plate. The first conductor pattern includes interleaved fingers of an interdigital transducer disposed on the diaphragm, and a first plurality of contact pads. A second conductor pattern is formed on a surface of a base, the second conductor pattern including a second plurality of contact pads. Each pad of the first plurality of contact pads is directly bonded to a respective pad of the second plurality of contact pads. A ring-shaped seal is form between a perimeter of the piezoelectric plate and a perimeter of the base.

A method of fabricating packaged electronic components with improved yield and at lower unit cost; the method comprising the steps of obtaining an active membrane layer on a carrier substrate, depositing a front electrode onto a front of the active membrane layer, obtaining an inner front section including at least a silicon handle or wafer, attaching an inner front end section to an outer surface of the front electrode, detaching the carrier substrate from a back surface of an active membrane on the opposite surface from the front surface on which the front electrode is deposited, patterning the active membrane layer into an array of at least one island of membrane, selectively removing the front electrode and bonding layer, selectively applying an inner passivation layer, and selectively depositing a back electrode layer on the thus exposed back surface of the active membrane.

Techniques are disclosed for forming high frequency film bulk acoustic resonator (FBAR) devices using epitaxially grown piezoelectric films. In some cases, the piezoelectric layer of the FBAR may be an epitaxial III-V layer such as an aluminum nitride (AlN) or other group III material-nitride (III-N) compound film grown as a part of a III-V material stack, although any other suitable piezoelectric materials can be used. Use of an epitaxial piezoelectric layer in an FBAR device provides numerous benefits, such as being able to achieve films that are thinner and higher quality compared to sputtered films, for example. The higher quality piezoelectric film results in higher piezoelectric coupling coefficients, which leads to higher Q-factor of RF filters including such FBAR devices. Therefore, the FBAR devices can be included in RF filters to enable filtering high frequencies of greater than 3 GHz, which can be used for 5G wireless standards, for example.

A front end module (FEM) for a 6.5 GHz Wi-Fi acoustic wave resonator RF filter circuit. The device can include a power amplifier (PA), a 6.5 GHz resonator, and a diversity switch. The device can further include a low noise amplifier (LNA). The PA is electrically coupled to an input node and can be configured to a DC power detector or an RF power detector. The resonator can be configured between the PA and the diversity switch, or between the diversity switch and an antenna. The LNA may be configured to the diversity switch or be electrically isolated from the switch. Another 6.5 GHZ resonator may be configured between the diversity switch and the LNA. In a specific example, this device integrates a 6.5 GHz PA, a 6.5 GHZ bulk acoustic wave (BAW) RF filter, a single pole two throw (SP2T) switch, and a bypassable LNA into a single device.

A front end module (FEM) for a 5.5 GHz Wi-Fi acoustic wave resonator RF filter circuit. The device can include a power amplifier (PA), a 5.5 GHz resonator, and a diversity switch. The device can further include a low noise amplifier (LNA). The PA is electrically coupled to an input node and can be configured to a DC power detector or an RF power detector. The resonator can be configured between the PA and the diversity switch, or between the diversity switch and an antenna. The LNA may be configured to the diversity switch or be electrically isolated from the switch. Another 5.5 GHZ resonator may be configured between the diversity switch and the LNA. In a specific example, this device integrates a 5.5 GHz PA, a 5.5 GHZ bulk acoustic wave (BAW) RF filter, a single pole two throw (SP2T) switch, and a bypassable LNA into a single device.

Design and processes are described for fabricating single-crystal bulk acoustic wave resonators with better performance and better manufacturability. A low-acoustic-loss single-crystal piezoelectric layer is epitaxially grown on a substrate, followed with the formation of bottom electrode, metallic cavity frames, and gap filler material on the piezoelectric layer. Matching metallic cavity frames and gap filler material are formed on a second substrate. The two wafers are then bonded together by metal-to-metal bonding of the metallic cavity frames on the first wafer to the matching metallic cavity frame on the second wafer to form a sealed cavity between the bottom electrodes and the second wafer. The first substrate is then removed to expose the piezoelectric layer. This second wafer and the structures thereon are then ready to complete the BAW resonator and filter fabrication using standard wafer processing steps.