An acoustic resonator device includes a substrate and a piezoelectric plate. A first portion of the piezoelectric plate is on the substrate. A second portion of the piezoelectric forms a diaphragm suspended over a cavity in the substrate. An interdigital transducer (IDT) is on a surface of the piezoelectric plate, the IDT including first and second busbars on the first portion and interleaved IDT fingers on the diaphragm. A plurality of tethers support the diaphragm over the cavity, each tether providing an electrical connection between a corresponding one of the interleaved IDT fingers and one of the first and second busbars.

A micro-transfer printable transverse bulk acoustic wave filter comprises a piezoelectric filter element having a top side, a bottom side, a left side, and a right side disposed over a sacrificial portion on a source substrate. A top electrode is in contact with the top side and a bottom electrode is in contact with the bottom side. A left acoustic mirror is in contact with the left side and a right acoustic mirror is in contact with the right side. The thickness of the transverse bulk acoustic wave filter is substantially less than its length or width and its length can be greater than its width. The transverse bulk acoustic wave filter can be disposed on, and electrically connected to, a semiconductor substrate comprising an electronic circuit to control the transverse bulk acoustic wave filter and form a composite heterogeneous device that can be micro-transfer printed.

A piezoelectric film that includes crystalline AlN; at least one first element partially replacing Al in the crystalline AlN; and a second element doping the crystalline AlN and which has an ionic radius smaller than that of the first element and larger than that of Al.

A vibrator device includes a package including a base that is a semiconductor substrate and a lid that is a semiconductor substrate and has a housing section, a vibrator element and a passive element housed in the housing section and placed at the base, an oscillation circuit placed at the base and electrically coupled to the vibrator element, and a mounting terminal placed at the package and electrically coupled to the passive element, and at least one of the base and the lid is coupled to fixed potential.

A bulk acoustic wave (BAW) device includes a substrate, a reflector on the substrate, a piezoelectric layer on the reflector and including a first opening through which a portion of the reflector is exposed, an electrode layer on the portion of the reflector exposed through the first opening, a passivation layer on the piezoelectric layer and a portion of the electrode layer and including a second opening through which a portion of the electrode layer is exposed, an under-bump metallization layer on the portion of the electrode layer exposed through the second opening and extending over the second opening and the first opening on the passivation layer, and a copper pillar structure on the under-bump metallization layer such that the entirety of the under-bump metallization layer is covered by the copper pillar structure.

An integrated circuit may include a resonator formed from FinFET devices. The resonator may include drive cells of alternating polarities and sense cells interposed between the drive cells. Each of the drive cells may include at least two drive transistors having fins coupled to a drive terminal. Each sense cell may include two sense transistors having one fin coupled to a sense terminal and another fin coupled to ground. Adjacent drive and sense cells may be separated by an intervening region that can accommodate a number of fins. Configured in this way, the resonator can exhibit a high quality factor, low phase noise, and can operate at a frequency that is less than the characteristic resonant frequency as defined by the fin pitch of the drive and sense transistors.

An acoustic resonator device includes an annular acoustic resonator, a heater coil and a heat sensor. The annular acoustic resonator is positioned over a trench formed in a substrate of the acoustic resonator device. The heater coil is disposed around a perimeter of the annular acoustic resonator, the heater coil including a resistor configured to receive a heater current. The heat sensor is configured to adjust the heater current in response to a temperature of the heater coil.

A piezoelectric thin film resonator includes: lower and upper electrodes located on a substrate and facing each other; a piezoelectric film sandwiched between the lower and upper electrodes and including lower and upper piezoelectric films, an outer outline of the upper piezoelectric film coinciding with or being located further out than an outer outline of a resonance region in a region surrounding the resonance region, the outer outline of the upper piezoelectric film being located further in than an outer outline of the lower piezoelectric film in the region; an insertion film interposed between the lower and upper piezoelectric films, located in an outer peripheral region within the resonance region, not located in a central region of the resonance region, and located on an upper surface of the lower piezoelectric film in the region; and a protective film located on the upper electrode in the resonance region, and located so as to cover an end face of the upper piezoelectric film and an upper surface of the insertion film in the region.

A method for manufacturing a piezoelectric resonator. The method includes: depositing a piezoelectric layer and forming a recess in a lateral area in such a way that a silicon functional layer is exposed inside the recess, forming a silicide layer on a surface of the silicon functional layer exposed inside the recess, forming a diffusion barrier layer on the silicide layer, depositing and structuring a first and second metallization layer in such a way that a supply line and two connection elements are formed, forming the oscillating structure by structuring the silicon functional layer, the silicon functional layer of the oscillating structure being able to be electrically contacted via the first connection element and forming a lower electrode of the resonator, the first metallization layer of the oscillating structure being able to be electrically contacted via the second connection element and forming an upper electrode of the resonator.

In a crystal oscillator, a crystal resonator plate is bonded to, via laminated bonding patterns, a first sealing member covering a first excitation electrode of the crystal resonator plate; and a second sealing member covering a second excitation electrode of the crystal resonator plate. An internal space is formed, which hermetically seals a vibrating part including the first and second excitation electrodes of the crystal resonator plate. The laminated bonding patterns include a laminated sealing pattern annularly formed to surround the vibrating part in plan view so as to hermetically seal the internal space, and a laminated conductive pattern establishing conduction between wiring and electrodes. The laminated conductive pattern is disposed within a closed space surrounded by the laminated sealing pattern. To the laminated sealing pattern, GND potential is applied when the crystal oscillator operates.